Talk:Prolactin

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Priority and significance of Friesen?[edit]

Can someone knowledgable have a think about whether the way Friesen is referenced is appropriate? I was doing a minor clean up of the opening section -- to make it easier for non-experts to follow -- and the Friesen reference was a problem.

On the one hand it said merely that he did "important later work". On the other hand, there are claims out there that he's pretty much the guy who gets credit for identifying prolactin in humans. If it's the former, then perhaps he should be removed completely (very few other sources -- except for a Canadian prize -- seem to credit him in that major way), or at very least perhaps some others should be added alongside him to show that he's not the only one who has done important work subsequent to Riddle. But if it's the latter -- i.e. if he *is* The Guy who found/confirmed human prolactin, than surely it should say that, and not merely "important later work"?

I had already taken the former approach -- removing his name -- but then I stumbled on his 1970 paper (it doesn't exactly leap out at you unless you know what you're looking for). So I switched to the latter approach, giving him specific credit. But to be honest, I really don't know. I'm not a medic, so I don't even know if that 1970 paper is seminal. I'm merely *enough* of an educated layman to know that as it stood, something smelled not just right about the way the opening section of the article was written.

While I'm here, is it also worth giving at least a minor nod to the two French dudes who seemed to have done the preparatory work, circa 1928, setting Riddle and pals up for the final dribble past the goalie and scoring in 1933?

Need broader scope in this article[edit]

This page could profit greatly from a contribution by a comparative endocrinologist. Prolactin is an ancient hormone and is found in all vertebrates. To limit the treatment of prolactin to lactating mammals is terribly incomplete. —Preceding unsigned comment added by Cthompson (talkcontribs) 15:41, 20 November 2007 (UTC)[reply]

While I am not an endocrinologist, I have added text to the Functions section of the article describing some of the functions of prolactin outside of lactation. TLopdell (talk) 04:47, 9 December 2018 (UTC)[reply]

prolactin elevation in celiac disease[edit]

Active ceoeliac disease added. Here are references for those in doubt:

  • Reifen, R.; Buskila, D.; Maislos, M.; Press, J. & Lerner, A. Serum prolactin in coeliac disease: a marker for disease activity. Arch Dis Child, 1997, 77, 155-7
  • Várkonyi, A. & Falkay, G. [Hyperprolactinemia in children with celiac disease] Monatsschr Kinderheilkd, 1984, 132, 547-9

212.202.0.156 10:19, 13 August 2005 (UTC)[reply]

Doubt is not the issue. The fact is that you are not providing any context. What does anyone care for the prolactin levels? There are 10,000s of diseases that could potentially affect prolactin levels, from anemia to Zollinger-Ellison syndrome. What is your point? Why does this snippet of scientific knowledge deserve mention in this article? JFW | T@lk 21:18, 14 August 2005 (UTC)[reply]

(1) Context: Coeliac disease is much more common than for example pituitary adenomas. So, why shouldn't it deserve to be mentioned? (2) If an article for an encyclopedia doesn't attempt to be at least a little bit complete it shouldn't be written at all. It's a question of quality IMHO.

212.202.201.235 22:35, 14 August 2005 (UTC) "What does anyone care for the prolactin levels?" Here is the answer: there are too many cases of silent celiac disease. In some cases, an elevated prolactin level is the only clue. For example, one family with a recently diagnosed T1DM teen learned from inpatient hospital testing that the teen also had silent celiac. Turns out the mom also has celiac. Her case was silent too. She was noted 25 years ago to have elevated prolactin and sought help from endocrinologists affiliated with UCLA. No explanation was found for the elevated prolactin and she was offered medication to lower the level (also to treat some physical symptoms she found embarrassing which were related to the elevated prolactin levels). Subsequently she delivered a child who was diagnosed with autism, and second child as a teen diagnosed recently T1DM. Given the incidence of autism is increased when the mother has autoimmune disease during pregnancy, perhaps a timely celiac diagnosis might have prevented the autism? Perhaps an awareness of celiac in the family might have alerted the family sooner to second child's T1DM? This second child arrived at the ER with A1c of 14.6 and had to be treated for DKA. Given celiac is more common than pituitary adenomas, I hope the above experience of this one family provides the "context" you are seeking. There is some evidence early treatment for celiac prevents additional autoimmune diseases, in which case the awareness of celiac in this family might also have prevented second child's T1DM. Arguing for ignorance seems harmful and foolish. Certainly this mother and the physicians at UCLA would have benefited from knowing about this connection between celiac and elevated prolactin when the mother was seen in the 80's. Now the information is available, let it be made properly available and included when appropriate. The important fact is celiac is common and often a missed diagnosis, and if elevated prolactin provides the clue which allows for diagnosis of the celiac, that justifies including the information here. —Preceding unsigned comment added by Hannahz31 (talkcontribs) 20:02, 15 November 2010 (UTC)[reply]

A pituitary adenoma directly produces prolactin. Anything else and we're arguing about why celiac disease deserves any more mentioning than xyz disease that also raises prolactin levels. Why is it interesting that celiac disease causes raised prolactin levels? Alex.tan 01:46, August 15, 2005 (UTC)

The section where I made the entry is "Hyperprolactinemia". I think it would make sense to give more than only one or two causes for hyperprolactinemia in such a section, coeliac disease being one of the more common causes. Other causes should be given as well in order to better reflect the current state of scientific research. To be more up-to-date would help to raise the usefulness and quality of the article. Nussey/Whitehead (and other books from PubMed's bookshelf) for example would be a good starting point for looking at what to add to the article, e.g. Major factors controlling prolactin secretion and causes of hyperprolactinemia. 212.202.0.165 10:09, 15 August 2005 (UTC)[reply]

So the question comes back to you, why does this not even mention coeliac? Can't we just agree to leave it out? JFW | T@lk 22:37, 15 August 2005 (UTC)[reply]

I can't tell you why Nussey/Whitehead (2001) didn't include it in their list. But a book has always limited space and authors have always limited capacities. It's only natural that they focus on selected issues. Two of the advantages of a collaborative online encyclopedia are more space and more authors. So, more issues can be, and should be IMHO, picked up and discussed. To "just...leave it out" is perhaps an economic decision, but not a scientific one. The "leave it out" approach is hardly appropriate for an encyclopedia that once set out to collect and distribute the knowledge of the world...

212.202.210.75 14:45, 16 August 2005 (UTC)[reply]

Dear 212.202.210.75, you're chewing a very old Wikipedia hot potato. Wiki is not paper, but it is also not a random collection of information. On the balance of things, I would discourage the mention of coeliac for the following reasons:
  • Its exact prevalence in coeliacs, and its contribution to hyperprolactinaemia is unknown.
  • Its clinical significance is undetermined, and likely to be limited.
  • Why would you determine prolactin in a coeliac if they do not have menstrual, hypogonadic of pituitary symptoms? JFW | T@lk 16:05, 16 August 2005 (UTC)[reply]

"Oldies but goldies." I would suggest the opposite, i.e. not only including c.d. but other diseases with hyperprolactinemia as well. The lack of statistical data is no reason for dismissing the fact. Because Wikipedia isn't a clinical handbook but rather addressing a broad circle of readers I can't see any problem with mentioning the fact. And you probably will agree that hyperprolactinemia -whatever the cause- is of clinical significance. Regarding your question, the answer is: e.g. in differential analysis of growth retardiation/hypogonadism of unknown etiology in children. C.d. is quite often overlooked as a cause. Another reason is detection of late-onset c.d., overlooked even more often.

212.202.0.202 09:09, 17 August 2005 (UTC)[reply]

I'm with JFW. What's the significance, clinical or otherwise, of hyperprolactinemia in celiac disease? Btw, "lack of statistical data" usually equals "insufficient evidence for this situation" rather than claiming this as fact. Alex.tan 14:18, August 17, 2005 (UTC)

It's time to ask Alteripse. He's a pediatric endocrinologist. JFW | T@lk 18:17, 17 August 2005 (UTC)[reply]

I have just reviewed what appear to be the major research reports and editorials on this topic PMID 14500322, PMID 14984168, PMID 9867122, PMID 9301358, PMID 6384457, PMID 15774013. Although it dates back to 1981, I have to admit to not having heard of this association and found it interesting. For another physician unfamiliar with the topic, I would compare it to the use of a sedimentation rate as a very crude indicator of "disease activity" for a patient with lupus or inflammatory bowel disease. Several reports suggest that it may be elevated in patients with active inflammation and villous damage from gluten but that it usually returns to normal when the patient follows a gluten free diet and the intestinal villi recover. In terms of sensitivity and specificity it is better compared to incomplete dex suppression as an test for depression rather than the equivalent of a HbA1c for diabetes care. Not all reports confirmed this finding and even after 20 years it clearly has not become a widely used measure of disease activity in GI clinics caring for children with celiac disease. It deserves at most a single sentence in a lengthy article about celiac disease or prolactin as a finding of current research interest whose clinical significance and usefulness has not yet been settled. I would certainly not rate it in the top 100 pieces of information for general articles about either celiac or prolactin. Is that a helpful synopsis? alteripse 01:57, 18 August 2005 (UTC)[reply]

Thanks. That sounds like a good summary. Alex.tan 06:17, August 18, 2005 (UTC)

Just a short update (references from Pubmed).

  • Stazi AV, Trinti B: [Reproductive aspects of celiac disease]. In: Ann Ital Med Int. 2005 Jul-Sep;20(3):143-57. [Article in Italian]
  • Pynnonen PA, Isometsa ET, Verkasalo MA, Kahkonen SA, Sipila I, Savilahti E, Aalberg VA: Gluten-free diet may alleviate depressive and behavioural symptoms in adolescents with coeliac disease: a prospective follow-up case-series study. In: BMC Psychiatry. 2005; 5: 14. [1].

Both articles refer to prolactin in the context of coeliac disease.

212.202.210.32

As this is a fairly obscure connection unknown to most pediatric endocrinologists and gastroenterologists, curiosity compels me to ask the following questions:

  1. Why do you think after nearly 25 years, the studies still look the same-- there is almost nothing in the most recent studies that wasn't implied by the early ones.
  2. There were also reports in the 1970s suggesting that prolactin might be useful in confirming that a spell was an epileptic spell, but it never caught on among neurologists. Do you think we should put that in also?
  3. Why do you think prolactin has not been adopted as useful in the clinical care of children with celiac disease by pediatric gastroenterologists?
  4. Finally, why are you so heavily invested in publicizing this connection?

Thanks for your answers. alteripse 18:59, 20 November 2005 (UTC)[reply]

The bit about seizures is actually at the end of the article; I've heard of this use of prolactin quite frequently, either positively or negatively. There is a reference (Ahmad et al) in the psychogenic non-epileptic seizures article. JFW | T@lk 20:14, 20 November 2005 (UTC)[reply]
Are you implying that I should actually read an article before commenting on it? -and don't you want to know the answers to those questions? alteripse 20:19, 20 November 2005 (UTC)[reply]

Regarding Alteripse's questions:

  1. If there is any causality I wouldn't expect different outcomes after 25 or after 50 years.
  2. I would suggest to include every single piece of scientific knowledge that could contribute to a better understanding of the possible causes of unusual levels of prolactin. There is plenty of room here to mark entries appropriately as occurring more commonly or rarely -- no need to keep the knowledge secret. If nobody ever incorporates new knowledge there will be no gain of new insight, no progress.
  3. Good question! But I'm the wrong person to ask. I can only speculate about the reasons. A starting point for an explanation could be that it is possibly a bootstrapping problem: Because of "most pediatric endocrinologists and gastroenterologists" didn't read or hear about it, they can't put it more frequently into practice. And because of it is so rarely written about this "obscure connection", they usually won't read or hear about it. But then that's only speculation.
  4. As a scientist, I'd prefer the picture to be more complete. I want to quote from other articles here to underline the importance of the problem:
"The delay in diagnosis of 106 patients with adult coeliac disease, diagnosed between 1976 and 1980, was studied. Overall, delay in diagnosis was 11 +/- 10.6 years, being considerably greater in females (12.8 +/- 7.8 years) than in males (3.5 +/- 9.8 years). Most of this delay occurred prior to hospital referral, although that following referral to hospital clinics was still significant (1.8 +/- 4.8 years). The most common presenting complaints were lassitude (75%) anaemia (65%) and flatulence (50%). Typical gastro-intestinal symptoms were relatively uncommon and mild, but when present led to a more speedy diagnosis. It is concluded that, despite advances in modern diagnostic procedures, little progress has been made in hastening the diagnosis of coeliac disease." [2]
That was in 1983. Since then, the situation has not much improved:
"Because the symptoms of celiac disease are vague, patients can complain for years before the diagnosis is made. Often, they are told they have irritable bowel disease or anxiety disorder. Doctor shopping is frequent." (1997) [3]
There are current studies with similar findings and conclusions.
I have made the acquaintance of a few people who are affected by atypical c.d. At least three of them had severe problems (not only) due to raised levels of prolactin prior to a change in their diet. (In one case the necessary medication with dopamine agonists to stop lactation brought almost no result. In most cases, however, prolactin had not been measured at all.) Afterwards, i.e. after maintaining a cereal-free diet for some months, the values (prolactin and others) normalized and the symptoms improved. But it was the patients who had to tell their physicians what was going on and not the other way around. Most of them had to suffer badly before -- for nine years on average. And that bothers me. As a human being I would say that if there is any statistical relevance of the connection between raised levels of prolactin and celiac disease it may help at least a few people to get the right diagnosis more timely. To make them suffer less. Withholding information wont't help. And it's not scientific either.

BTW: October was, once again, "Celiac Awareness Month". [4] 212.202.198.158 10:21, 21 November 2005 (UTC)[reply]

Thanks for an elaborate answer but it answered a different question than I asked. I would dispute a point and hone the main unanswered question. In our hospital pediatric endocrinologists and gastroenterologists have indeed been talking to each other about celiac disease in recent years. It is the hottest GI topic in endocrinology, as we have over the last few years begun to adopt yearly celiac screening for all children with type 1 diabetes. This has involved scrutiny of screening tests as well as prolonged discussion over the value of making the diagnosis in the asymptomatic. Since the 1970s, endocrinologists have routinely looked for celiac disease in unexplained growth failure, in unexplained vitamin D deficiency, and in diabetic children with abdominal symptoms. The gastroenterologists have long favored antibody screens rather than hormone screens as being more sensitive and specific, and even endocrinologists used the anti-gliadin antibody in the 1980s, anti-endomysial antibodies in the 1990s, and more recently anti-tissue transglutaminase IgG and IgA. So my question and implied criticism were focused very specifically on the prolactin test, not on the value or importance of making the diagnosis of celiac as you answered. There are tests that are so valuable that they become adopted quickly and there are those that never become popular in practice, and the prolactin is clearly in the latter category. It seemed strange to me that someone would so persistently be pushing a really obscure piece of information that has not been found useful by the specialists most involved. alteripse 11:44, 21 November 2005 (UTC)[reply]

Maybe you got me a little bit wrong. What I would suggest is to mention that in cases of inexplicable hyperprolactinemia searching for c.d. could make sense. Nothing more. But nothing less, too. To provide just one more clue for those seeking information.
Regarding your last contribution...
By my knowledge the antibody tests are quite reliable but nevertheless they can not provide 100% certainty (as many other tests can't). Tests fail. Individual conditions matter. For example in cases of selective IgA deficiency, diagnosis is harder. Sometimes the results of IgX tests fall in a grey area (depending on national standards) and biopsy is inconclusive. Most physicians tend to exclude c.d. in such cases. And not in every country IgX tests are common practice at all.
Also there are cases of other illnesses in which the co-occurence of c.d. is not detected, not even thought about. Take Grave's disease as an example. One of the above mentioned acquaintances suffered for almost 10 years from diarrhoea, hallucinations and other symptoms. She has Grave's disease since she was 9 (she is now in her mid-thirties) and was lately diagnosed with IBS, malnutrition, and psychotic disturbances. Four weeks of strictly gluten-free diet greatly improved her condition. No more diarrhoea, no more hallucinations. (But even tiny doses of gluten in her food -those "traces" mentioned in the small-print of the food packages- can give her a new break-down. She has learned that lesson the hard way and now she is most careful.)
For years she has been a member of a self-help group and so she told the other members about her experiences. She explicitely asked them whether they had been screened for c.d. The result, you guess it, was, no, they hadn't. And the co-occurrence of Grave's disease and c.d. isn't so infrequent at all (just browse PubMed). A screening would make sense [5].
But it took years to arrive at such insight. Maybe it will also take years to start looking for c.d. in cases of inexplicable hyperprolactinemia. 212.202.198.158 12:46, 21 November 2005 (UTC)[reply]

But what does Grave's have to do with prolactin? You have cited no evidence that checking for coeliac disease in unexplained hyperpprolactinaemia is actually sensible. What is the diagnostic yield? Are you suggesting everyone with unexplained symptoms should go on a gluten-free diet? JFW | T@lk 00:03, 22 November 2005 (UTC)[reply]

In at least some cases of c.d. the prolactin level is raised significantly. It normalizes after maintaining a gluten-free diet. That is what the literature shows (consistently for almost 25 years). Hyperprolactinemia may point to c.d. So if you have to explain what causes hyperprolactinemia in a patient you should consider to rule out, among other possible causes such as adenoma, c.d. To quote myself: "What I would suggest is to mention that in cases of inexplicable hyperprolactinemia searching for c.d. could make sense." I don't want to suggest anything else. (The example of Grave's disease should only illustrate that what was obscure some years ago is now recommended as a standard test.) 212.202.198.158 01:05, 22 November 2005 (UTC)[reply]

So I will ask you again: what percentage of hyperprolactinaemic patients with no obvious cause turns out to have CD? JFW | T@lk 01:20, 22 November 2005 (UTC)[reply]

Prolactin in non-mammals[edit]

This article seems to treat prolactin as being peculiar to mammals, or even to humans (the article should clearly indicate when humans are being discussed, as opposed to mammals in general), but the DVD The Blue Planet: Seas of Life: Seasonal Seas / Coral Seas, in the Fact Files part of the Special Features section, says:

Male seahorses even release the same hormone—prolactin—as female humans.

If this is literally true, it seems some expansion of the scope of the article is called for. - dcljr (talk) 00:35, 7 August 2006 (UTC)[reply]

What to include/exclude...the old arguement.[edit]

Speaking as an educated non-specialist, I think there these are important points:

One of the main advantages of an online encyclopedia is that it can, in theory, be kept up to date keeping nearly even with new research. Therefore, items with known correlations should be included somewhere in the article, or at least in a page linked to the article. When we know only part of the relationship, we should put what we know, and update it as new data is learned.

Of course, one of the many forms of update will include removing (or better moving to another page and referencing under 'history') research which is, on reconsideration not accurate.

One reason for saving the history is that sometimes, a 'blind-alley' turns out not to have been so blind, and to leave out mention of the historical view of the subject, the new researchers will have less of an idea of what data has been collected.

Another is that studies often collect data which might be viewed from a different perspective and ad insight to some other unrelated study.

What has to happen is that historical belief has to be separated from the current understanding.

We do not talk about physics on the human level (i.e. Levers & other simple machines) which work well under the Newtonian physics in terms of quantum physics, even though the end result is the same, and the Newtonian physics is, on some level, an 'inaccurate' model of the process. Some models are easier to understand and apply than others and they are used where they do not directly contradict 'more complete' models.

An encyclopedia, by nature, is an attempt to collect as much as possible into a limiteds space. This, because data storage space is not the same as physical storage, is no longer a correct way to define encyclopedia, since an online version can be both 'unabridged' and 'comprehensive.' Ideally, an online encyclopedia either contains or is linked to everything which has ever been said about a topic.

The question is not what to include, it is WHERE to include things.

The main entry should contain multiple references to causes for this syndrome, but they ought to be cases where there is a clear correlation. Less clearly correlated cases should be relegated to a lower level page, or to links to external studies.

IMHO Wizodd 18:05, 10 March 2007 (UTC)[reply]

Effects on tesosterone production[edit]

This article states a function is:"* To decrease normal levels of sex hormones — estrogen in women and testosterone in men."[4] " The sourcing is pretty poor. Ken Saladin states that in the male it results in "increased LH sensitivity and testosterone secretion" (saladin, p. 643 4ed.) Any clarification on this one? --203.217.79.99 (talk) 09:59, 14 July 2008 (UTC)[reply]

Cause and effect[edit]

Problems with subsection titles:

  • "Conditions caused by elevated prolactin secretion"
    • "Pregnancy" - not caused by elevated prolactin. It's the other way around: elevated prolactin is caused by pregnancy.
    • "Many anti-psychotic medications" - Hopefully I don't need to explain this one...
  • "Conditions caused by decreased prolactin"
    • "Bulimia" - evidence suggests that bulimia is caused by excess prolactin, not vice versa.
    • "Excess dopamine" - again, cause and effect is being mixed up.

Now, there are two renaming choices to rectify this. There could be four sections, "Conditions causing increased prolactin", "Effects of increased prolactin", "Conditions causing decreased prolactin", and "Effects of decreased prolactin". That would make the most sense. Currently though, I just switched the wording of the current sections to "associated with" rather than "caused by". In any case, this is a classic mix-up of correlation and causation.Fuzzform (talk) 05:00, 20 December 2008 (UTC)[reply]

It says prolactine causes neurogenesis. As far as I know (and after a quick google search), it is progesterone that causes neurogenesis, and therefore is given after traumatic brain injuries. — Preceding unsigned comment added by 217.132.238.122 (talk) 07:19, 22 June 2011 (UTC)[reply]

Effects on female sex drive[edit]

The following paragraph is unsourced, and I find it questionable:

Increasing prolactin levels in women during pregnancy (especially within first 3 months) and then in the breastfeeding period are responsible for cycles of high sexual satiation, which help protect the child and are amidst natural rewards for procreation. However, fluctuations and drops of this hormone occurring in that period can substantially increase sexual tension and in turn often work for higher desire for orgasms.

Also, it's written unclearly -- I can't tell whether "high sexual satiation" means that sex is very fulfilling, or that the individual feels sexually satisfied much of the time, and thus has less interest in sexual activity. Similarly, I'm not sure whether "higher desire for orgasms" and "increase[d] sexual tension" indicate that sex has become more enjoyable, or that the individual feels less of a response to sex, and has increasing amounts of sex in an effort to feel satisfied. Inhumandecency (talk) 23:38, 25 September 2009 (UTC)[reply]

test —Preceding unsigned comment added by 202.129.234.230 (talk) 06:52, 12 January 2010 (UTC)[reply]

Use of breastfeeding as contraceptive[edit]

This lacks sources and belongs to either breastfeeding and/or contraception but not this article. Leaving it here if someone wants to reuse elsewhere.

The World Health Organization states that under special conditions demand breastfeeding is more than 98% effective as a contraceptive in the first six months postpartum.[citation needed] This effect is said to be responsible for the natural spacing of children seen in countries where contraception is not widely available, and is thought to be an evolutionary means of ensuring adequate care is provided to each newborn. The 98% effectiveness applies only if three criteria are met:
  1. The mother has had no menstrual periods at all (amenorrhea)
  2. The baby is exclusively breast-fed
  3. It is six months or less since birth.
  • A fourth criterion has also been mentioned: The baby does not go for longer than 5 hours between feedings (i.e. while sleeping)
If one or more of these conditions are broken, lactational amenorrhea is no longer a reliable form of birth control. This contraceptive method is highly effective as long as the three conditions stated above are fulfilled. Further, the WHO suggests that a woman who is still amenorrheic has a less-than-5% chance of getting pregnant in the first year of her baby's life, as long as she is still breastfeeding on demand.

Richiez (talk) 20:46, 15 November 2010 (UTC)[reply]

Here is one source giving realistic estimate of reliability in modern circumstances, reliable "up to 9 weeks pp" with plenty of restrictions - PMID 8119562 Richiez (talk) 23:30, 15 November 2010 (UTC)[reply]

typical range[edit]

I found PMID 11297584, looking for more. Richiez (talk) 23:33, 10 March 2011 (UTC)[reply]

I've found two sources that both state typical prolactin values. One study uses several hundred men and is from 1975. The second study uses over 1,000 men (including over 900 healthy controls). Both establish the value to be between 10 and 11 ng / mL. Not coincidentally, this is right smack in the middle of the WHO range for normal. Both of these citations are from respected medical journals. I see no justification for your removal of my edits. StructureWiki (talk) 00:55, 11 March 2011 (UTC)[reply]

what is ng/dL? I would suggest using µg/L and giving conversion factors. I do not know if you tracked the TSH reference discussion in detail but there is an even bigger mess with prolactin because of macroprolactins. Using a source from 1975 is not possible, just as you can not do that with TSH referecne range.
Now, one thing is a reference range, above of which you have hyperprolactinemia. That range is defined by the assay you use. The other thing is the typical expected value for a healthy control of a certain age at a certain time of day and for women at considering the variation throughout the cycle. This is not so easy to get a comprehensive reference for.
PMID 10216513 has a somewhat more recent and detailed analysis although I hope I can find better references. Richiez (talk) 10:53, 11 March 2011 (UTC)[reply]
A quick note before I begin: ng / dL is nanograms per deciliter. I've used this in my edits erroneously; it should read ng / mL (nanograms per milliliter). Nanograms per milliliter is mathematically equivalent to micrograms per liter (µg / L). Some publications use one while others use the other. Before I started editing this page, the units being used were ng / mL. I don't care if you want to switch it to µg / L; they are equivalent. However, we need to be consistent: we should use the same units throughout the page and not switch between one and the other (for example, the section on WHO reference ranges uses ng / mL).
Now, let's break down what we are trying to do in more detail so that we can find common ground.
First, let's recognize that the section we are editing is titled "Reference Levels." The intention here is to provide some information regarding prolactin levels in humans. You've mentioned that prolactin levels vary during the day; this is true. However, it is not unique; the majority of hormones in the human body are pulsatile in nature, which is why reference ranges are typically established for AM blood draws (usually while fasting). After all, doctors still need to establish a normal range. Prolactin is no exception; reference ranges are AM. Other examples of pulsatile hormones with AM reference ranges include LH, FSH, T, DHT, E2, TSH, etc.
The "Reference Levels" section starts off just fine: reference ranges are provided for both men and women, as described by a publication from the world health organization. So far, so good. Since women's levels vary significantly by age, some labs break down the normal prolactin ranges into age groups. Sometimes, hormone reference ranges are further divided by phases of the menstrual cycle (for example, FSH). If you'd like to add any of this information to the page, I won't stop you. As it is, we only have one range, the one provided by the WHO. I have no problem with this section as it is well sourced.
The section I do have a problem with directly follows the WHO reference ranges. This is how it appeared before I modified it:
When measured under normal conditions in the morning most values fall into the range 4-12 ng/mL for women and 2-4 ng/mL for men. Measurement at other times of the day or after stress exposure will yield different values.
There's a couple of problems here:
  1. The information is not backed up by any citations at all.
  2. The information is factually incorrect.
My intentions are twofold:
  1. Correct the information.
  2. Provide citations that back up the newly corrected information.
Now, let's look at my proposed changes:
Prolactin levels significantly decrease with age in women, and slightly increase with age in men.[18] The average prolactin level in men is between 10 and 11 ng / mL[19][18]. The average prolacin level in women between the ages of 15 and 25 is approximately 20 ng / mL, and steadily decreases with age; women 55 and older have average prolactin levels similar to men.[18]
I'm using two citations here, one from 1975 and another from 2009. The one from 2009 plainly supports the statement "the average prolactin level in men is between 10 and 11 ng / mL." The paper measured prolactin levels in 942 healthy men, and 572 men with cardiovascular problems. Their finding was: "Prolactin levels did not differ between cases and controls; for men 10.2 ug/L versus 9.9 ug/L..." In addition to the 2009 paper, I've used the 1975 article as supplementary evidence. I say supplementary because the 2009 citation is strong enough evidence without an additional citation. However, both papers are in agreement, and both papers use hundreds of healthy men to establish these values. The assumption is that the result is likely correct. The block of text that I'm replacing, the one that you seem to prefer in its stead, has no citation at all to support it.
The statement that "prolactin levels significantly decrease with age in women, and slightly increase with age in men" is backed up exclusively by the 1975 reference. I'm sure we can find a more recent source for this information, since it is plainly obvious. However, even with an old, outdated assay, relative concentrations can be determined (i.e. you can still tell that the serum prolactin concentration is decreasing with age in women even with older assays). If you want to replace the citation with a newer one, feel free. Hell, even put a note on the citation that says "I don't like this citation because it is from 1975." But don't remove the information unless you think it is inaccurate.
Lastly, there is the statement "The average prolacin level in women between the ages of 15 and 25 is approximately 20 ng / mL, and steadily decreases with age; women 55 and older have average prolactin levels similar to men." This statement also is backed up exclusively by the 1975 reference. Again, this statement should only be removed if you think it is inaccurate.
To sum it up, my objections are:
  1. The statement regarding prolactin levels in men is well sourced with a very large and recent study (2009), and should not be deleted.
  2. The statements regarding prolacin levels in women are accurate, and while the citation is old (1975), these statements are still better than the text that they replace because the old text has absolutely no citations to support it (not to mention that it is just plain wrong).
  3. You are not showing any selectivity in your reversions. If you have a problem with some of my edits, then improve them; don't just blindly revert.
  4. Even a statement sourced by an article from the 1975 British Medical Journal is better than an unsourced statement. Don't remove the information because the source is old; remove information if it is inaccurate! If the information is not incorrect, then add a newer source if you can find one. If you are going to say that information is inaccurate, then replace it with the correct information, but back it up with a source! StructureWiki (talk) 21:02, 11 March 2011 (UTC)[reply]
What does the "(Data from The Immunoassay Handbook, Third Edition)" relate to?
There are some problems with the data. The 2009 reference says "only a single, nonfasting, blood sample was used to characterize individuals with respect to prolactin concentration. This may have resulted in random measurement error because of intraindividual variation in prolactin with diurnal and episodic variation. " The prolactin values of men and women differ by less than 10% (Tables 2,3), most certainly they used a highly nonstandard measurement method and the data is not usable. Data of 65 year olds can not be used to define reference range for prolactin, you would not do this with estrogen. The objective of the study was something different. It would be interesting to have data of 65 year olds but I am highly sceptical of this particular data set.
The whole reference range thing is completely useless as it is now. For women its a bit hard to get good prepubertal data, to get an idea what typical ages 14-40 would look like look at PMID 14674722 (suggesting 4-12ng/ml typical value). For males, look at eg PMID 9509065. Richiez (talk) 01:03, 13 March 2011 (UTC)[reply]

I am perfectly sure that this version is the more correct one but am not willing to search sources and piece them together for hours. I gave you some references and can give a few more but my knowledge comes pieced together from thousands of studies which did study effects of various medications and such.

When measured under normal conditions in the morning most values fall into the range 4-12 ng/mL for women and 2-4 ng/mL for men. Measurement at other times of the day or after stress exposure will yield different values.

Here is the other version. It is wrong and I prefer giving no information instead of wrong information.

Reference Levels

ng/mL mIU/L Prolactin Standard
Women 2.8-29.2 59-619 (World Health Organization [WHO]: Third International Reference Preparation [3rd IRP] of prolactin, human, lyophilized, 0.053 IU / ampoule, for immunoassay [preparation code:84/500][1])
Men 2.1-17.7 45-375 (WHO: 3rd IRP 84/500)

(Data from The Immunoassay Handbook, Third Edition.[2])

Prolactin levels significantly decrease with age in women, and slightly increase with age in men.[3] The average prolactin level in men is between 10 and 11 ng / mL[4][3]. The average prolacin level in women between the ages of 15 and 25 is approximately 20 ng / mL, and steadily decreases with age; women 55 and older have average prolactin levels similar to men.[3]

  1. ^ "WHO Expert Committee on Biological Standardization" (PDF). Thirty-ninth Report, WHO Technical Report Series. World Health Organization. 1989. Retrieved 2009-06-03. 86.1520, WHO/BS documents: 86.1520 Add 1, 88.1596 {{cite web}}: Cite has empty unknown parameter: |coauthors= (help)
  2. ^ Wild D, ed. (2005). The Immunoassay Handbook (Third ed.). Kidlington, Oxford, UK: Elsevier Science. p. 930. ISBN 0080445268.
  3. ^ a b c Vekemans M, Robyn C (1975). "Influence of age on serum prolactin levels in women and men". Br Med J. 4 (5999): 738–9. doi:10.1136/bmj.4.5999.738. PMID 1212585. {{cite journal}}: Unknown parameter |month= ignored (help)
  4. ^ Reuwer AQ, Twickler MT, Hutten BA, Molema FW, Wareham NJ, Dallinga-Thie GM, Bogorad RL, Goffin V, Smink-Bol M, Kastelein JJ, Boekholdt SM, Khaw KT (2009). "Prolactin levels and the risk of future coronary artery disease in apparently healthy men and women". Circ Cardiovasc Genet. 2 (4): 389–95. doi:10.1161/CIRCGENETICS.109.853572. PMID 20031611. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

Richiez (talk) 13:04, 13 March 2011 (UTC)[reply]

Here is a paper that analyzes the prolactin levels of 2,531 men, and found that those with prolactin levels less than 5 ng / mL are associated with metabolic syndrome, anxiety, arteriogenic erectile dysfunction, and premature ejaculation:
Corona G, Mannucci E, Jannini EA, Lotti F, Ricca V, Monami M, Boddi V, Bandini E, Balercia G, Forti G, Maggi M. Hypoprolactinemia: a new clinical syndrome in patients with sexual dysfunction. J Sex Med. 2009 May;6(5):1457-66. Epub 2009 Feb 10. PMID 19210705

Our findings demonstrate that, in subjects consulting for sexual dysfunction, PRL in the lowest quartile levels are associated with MetS and arteriogenic ED, as well as with PE and anxiety symptoms.

Note: this pathologic range is the one you claim is normal. Prolactin levels < 5 ng / mL constitutes hypoprolactinemia.
Here's another paper stating other harmful effects of hypoprolactinemia:
Gonzales GF, Velasquez G, Garcia-Hjarles M. Hypoprolactinemia as related to seminal quality and serum testosterone. Arch Androl. 1989;23(3):259-65. PMID 2619414
Abstract

Semen quality and serum testosterone were studied in six men with hypoprolactinemia (less than or equal to 6 ng/ml) and in normoprolactinemic controls. The incidence of hypoprolactinemia in 92 men attending an infertility clinic was 7.5%. Males with hypoprolactinemia showed in high percentage of disorders (oligozoospermia, 50%; asthenospermia, 75%; hypofunction of seminal vesicles, 67%; and hypoandrogenism, 67%). Hypoprolactinemia is a clinical disorder associated mainly with poor sperm motility.

And another:
Ufearo CS, Orisakwe OE. Restoration of normal sperm characteristics in hypoprolactinemic infertile men treated with metoclopramide and exogenous human prolactin. Clin Pharmacol Ther. 1995 Sep;58(3):354-9. PMID 7554710
Abstract

We investigated the effects of induced increase in prolactin levels on spermatogenesis in 20 infertile men with hypoprolactinemia using exogenous human prolactin (hPRL) and metoclopramide. The subjects were selected from a population of 175 infertile men in whom the prevalence of hypoprolactinemia was 33.14%. Mean basal plasma prolactin was 2.79 +/- 0.62 ng.ml-1 in the infertile men and 9.57 +/- 2.14 ng.ml-1 in the normal control subjects. At the sixteenth week, mean plasma prolactin was 9.41 +/- 1.3 ng.ml-1 in subjects treated with exogenous hPRL and 5.2 +/- 0.7 ng.ml-1 in subjects treated with metoclopramide. Mean basal sperm concentration was approximately 8.8 million per milliliter in the infertile men and 41.5 million per milliliter in the normal control subjects. Mean sperm concentration was approximately 37 million per milliliter in subjects treated with exogenous hPRL, whereas the peak mean value was 23 million per milliliter in subjects treated with metoclopramide for 16 weeks. At basal conditions, the mean percentages of abnormal sperm were 66.75% +/- 14.93% and 21.36% +/- 4.78% in infertile and normal subjects, respectively. In subjects treated with exogenous hPRL and metoclopramide, the mean percentage of abnormal sperm were 24.7% and 31%, respectively, at week 16. Mean plasma prolactin, mean sperm concentration and the mean percentage of abnormal sperm were 3.3 +/- 1.4 ng.ml-1, 7 million per milliliter, and 60.5, respectively, in the infertile subjects after drug withdrawal at week 14. In normal control subjects, there was no significant difference (p = 0.01) in the plecebo effect. We therefore conclude that the low prolactin levels in this group of infertile men may be one of the primary causes of their infertility.

How much evidence do you need to see??
The unsourced information that normal prolactin levels in men is between 2-4 ng / mL is so egregiously wrong, I looked into the history to see who added it. Not surprisingly, I found that it was you (in revision 20:34, 12 August 2010). And now your aim is to prevent others from adding the correct information? At least at Wikipedia, you can't do this. Wikipedia is not a forum for you to publish your personal opinions or your original research, regardless of how right you think you are. StructureWiki (talk) 17:20, 13 March 2011 (UTC)[reply]
None of the sources you suggest makes the claim to establish or report the reference or physiological range of prolactin. None of your sources states that it reports the basal prolactin level. All your sources are unsuitable for what you want to prove. Richiez (talk) 18:48, 17 March 2011 (UTC)[reply]

prolactin reference levels[edit]

PMID 18719199 has the exact ranges of the various assays on the market. The current version (done by StructureWiki) reports completely bogus values so I am removing the section for now. Maybe it can be rewritten using the new information but I am not sure if it is worth the effort given the large intra-assay variance.

Btw afaics there is not even a universally accepted conversion factor from ng/ml to mIU/L - I have seen anything from 24 to 36 used as conversion factor.Richiez (talk) 18:59, 17 March 2011 (UTC)[reply]

Thanks, StructureWiki and Richiez, for your points on how reference ranges should be given. I think it's a good idea to include reference ranges of several assays, just to illustrate the point that they vary with assay method, such as:
Reference ranges for prolactin vary with what assay method is used, as illustraded with some commonly used methods in table below, taken from a control group of healthy health care professionals in Essex, England:<ref>Table 2 in PMID 18719199</ref>
Males 			
Access		58 	277 	
Centaur 	63 	262 	
Immulite 	70 	281 	
Elecsys 	72 	331 	
Architect 	85 	310 	
AIA 		89 	365 
Females 			
Centaur 	71 	348 
Immulite 	75 	396 	
Access		77 	408 
Elecsys 	88 	492 	
Architect 	98 	447 	
AIA 		105 	548 
, using a wikitable instead of formatting like this. Mikael Häggström (talk) 05:31, 19 March 2011 (UTC)[reply]
I think that would be good as a demonstration. In the meantime I have had a detailed look at the Immulite assay, the manufacturer published some interesting data here. The data is certainly very interesting, giving ranges for all ages (even neonates by days) and (female) cycle and pregnancy phases. Let me know if anyone needs help with translation. BTW it is no surprise that neonates have very high values but learning that they have much higher values than pregnant women was certainly new for me. Richiez (talk) 22:35, 19 March 2011 (UTC)[reply]
I added the table to the article. I think data from that siemens source should be added as well, still with a note that it's derived from specific control groups of usually between 20 and 50 people and using the IMMULITE assay, to avoid anyone getting the idea that the data can accurately be used for any individual in the world. Mikael Häggström (talk) 08:51, 20 March 2011 (UTC)[reply]
Thanks for doing the tables. The Immulite sample data might fit very good into the "Variance in levels" section. Together with this we have most of the details we need for that section. Richiez (talk) 10:42, 20 March 2011 (UTC)[reply]
I agree it's a good start. I had to fix the "Units" section up a bit first, because it's confusing trying to add reference ranges without knowing what the values represent. Anyone, feel free to correct if that section appears incorrect. Mikael Häggström (talk) 11:46, 20 March 2011 (UTC)[reply]
Hi Mikael, I'm glad to have you on board. I've long been a big fan of your work on the steroidogenesis chart.
After reading your edits on the units section, I was inspired to look into how the prolactin standard evolved. I found that the 1963 paper is not actually the 2nd standard for human prolactin immunoassays; rather, this paper predates the WHO's standardization of human prolactin. Apparantly, the WHO used animal prolactin standards before it was possible to use human prolactin reference preparations (see article for more info). I've uncovered the history of the standard, and modified the units section accordingly. The way that the IU is determined for polypeptide hormone assays is fascinating (see this paper http://www.ncbi.nlm.nih.gov/pubmed/1477965 for a thorough overview). As you will see, the conversion between IUs and g is determined by the international standard that the measurements are calibrated against. It is worthwhile to mention that conversions are unambiguous for a given international standard, despite the fact that reference preparations used in these standardizations are a bit of a black box: the exact purity and composition of reference samples is unknown. This is exactly why international studies are organized for the purpose of determining the ratio of IU:g for a given international reference preparation, and the need for consensus before assigning the final IU value to the IS ampoules.
I've also made some modifications to the International_unit#Equality_and_equivalency_of_IU_for_different_substances section, given what I've learned about how these standards are determined. Let me know what you think. StructureWiki (talk) 00:03, 22 March 2011 (UTC)[reply]
Thanks for updating the IU, both here and in its main article! It's a whole lot less confusing to me now, and hopefully to everyone that will read the article. I'm a bit uncertain about the need for so much details about individual ampoules, however, but I guess it doesn't harm. Mikael Häggström (talk) 16:42, 22 March 2011 (UTC)[reply]

I've added mean values, and have converted the values in the chart from mIU/L to ug/L. In case there is any dispute remaining about how to perform this conversion: the paper in which the units appears explicitly lists which reference preparations are used, and how to perform the conversion. All assays calibrated their measurements against IS 84/500 except for AIA, which used IS 83/562:

We measured prolactin with the Access 2 (Beckman Coulter), ADVIA Centaur and Immulite 2000 (Siemens Diagnostics), AIA 1800 (Tosoh), and Architect (Abbott) and Elecsys 2010 (Roche Diagnostics, prolactin II assay). Immunoassays were calibrated against the WHO third international standard for prolactin, IS 84/500, except for the AIA, which used the second international standard, IS 83/562. Prolactin units (in mIU/L) can be converted (to ng/mL) by dividing by 21.2 (Access, Architect, Centaur, Elecsys and Immulite) or 27.0 (AIA).

StructureWiki (talk) 00:34, 22 March 2011 (UTC)[reply]

Regarding the median values: they are interesting but must be used with more caution. I think this data would be much more useful to demonstrate age-dependent changes because otherwise it does contradict the reference ranges given in the table bellow. On the other hand the example table of reference ranges should probably state that it is suitable for a relatively narrow age group.

The article does not mention when to make the measurement and as far as I know the classical wisdom is after 9:30 or 2 hours after waking up. However after looking at PMID 9506722 (esp http://jcem.endojournals.org/cgi/content/full/83/3/761/F2) I would say that for men the resulting measurement will be suboptimal as it may in fact coincide with a singificant spike and a measurement 2 hours later would provide more stable values. Does anyone have a source explicitly saying that?

Regarding unit conversion: I am pretty strongly opposed to convert the reference ranges given by Beltran to µg/ml. Stick to the original source - in fact I do not see how the converted values were calculated??

The history of conversion values is interesting but it is very misleading to claim that there is one widely accepted conversion factor by now. PMID 1477965 is a bit dated and other factors have been used much more recently - please do not delete references to a recent large meta-analysis (PMID 19880787) showing that a factor of 30 is frequently in use. This is not some historic artifact, PMID 17573902 used this value in 2007 and I could list other post-2000 sources also using significantly different values.

Unless an authoritative source later than PMID 1477965 can be found do not present the WHO method as authoritative.

Part of the trouble with the conversion values may be that the earlier standards by WHO did not address the interaction of the assays with macroprolactin which was little known before 1995. In situations where you have ruled out macroprolactinemia or use a specially adapted/preprocessed assay method this may give researchers motivation to use different conversion factors, or better no conversion at all. The publication of Bertran does explicitly deal with macroprolactinemia so if he does not publish the values in µg/ml there may be a good reason for this. There may be more interactions than macroprolactin (somatolactin and any number of prolactin-like proteins) that may need further assesment. Richiez (talk) 12:14, 22 March 2011 (UTC)[reply]

It's obviously a fact that other conversion factors are used as well, so I prefer at least mentioning them, as in this revision. Although is makes the article a bit more complicated, it reflects that so is the reality too.
I haven't seen any information as to when samples should be taken. Ideally, there should be a study of reference ranges for different times during the day. Mikael Häggström (talk) 17:26, 22 March 2011 (UTC)[reply]
as for when to take samples PMID 3732539 apparently sets the rules for women. I do not see anything like that for men which is a bit pitty. Richiez (talk) 21:44, 22 March 2011 (UTC)[reply]

I think I was looking at the wrong table so I have not such a strong opinion about converting the tables but still think that I would leave them as they were originally published . Richiez (talk) 15:37, 22 March 2011 (UTC)[reply]

Alternatively, both µg/L and mIU/L may be given, perhaps with a note to the different conversion factor used for AIA. I'd prefer this. Mikael Häggström (talk) 17:25, 22 March 2011 (UTC)[reply]

The issue of IUs and their conversion factors is a confusing topic, but it is not misleading to say that only one conversion factor is used for a particular reference preparation --- this is exactly the purpose for establishing an IS: so that measurements can be calibrated against it. The more you look into the different conversion factors used, the more you'll see that the conversion factor depends on the reference preparation used to calibrate the samples against.

If you read PMID 1477965, you'll gain a much better understanding of how all of this works. The fact that it was published in 1992 is irrelevant: it describes the WHO's motivation (e.g. structural diversity / uncertainty in reference preparations due to the nature of polypeptide hormones) as well as their procedure used in determining the IS. Furthermore, the current prolactin standard is still IS 84/500, so in the unlikely case that significant changes have occurred that affect how an IS is determined, it would not affect the prolactin standard.

As you've mentioned PMID 19880787 refers to two papers that use 30 as a conversion factor. One of these papers was published in 1979, and the other in 1983. Since the IS 84/500 ampoules did not exist at that time, measurements could not possibly be calibrated to them, and thus a different conversion factor would be used.

you have missed that PMID 17573902, published in 2007 also uses conversion the factor 30. So clearly that factor is still in use long after the "other standard" has been established. Also, one of the assays still uses a value of 27.2.
PMID 17573902 makes no claim that it is calibrating its measurements against IS 84/500 (please re-read paragraph below regarding this --- I've highlighted in in bold).StructureWiki (talk) 00:45, 23 March 2011 (UTC)[reply]

If we are to modify the article (either this article, or the one on IUs in general) to imply that an IS does not impart an unambiguous conversion factor, we should at least be able to supply evidence of this. Specifically, show me some papers that refer to measurements being calibrated against the IS 84/500 ampoules that do not use 21.2 as the conversion factor. From what I have read, this conversion factor is unique to IS 84/500 because its ampoules contain 2.5 micrograms, and have been assigned the activity of .053 IUs. Mathematically, this yields the ratio of 21.2.

We have perhaps 5 or 6 different conversion factors (I am also aware of 23.8), at least 4 of that have been used or published later than 2000. We do not need to decide which one is correct but should list them all or easier say that any number of conversion factors ranging from 21.2 to 30 are in use. There are certainly more interesting aspects of prolactin that deserve work. Richiez (talk) 22:00, 22 March 2011 (UTC)[reply]
I think you might be a bit confused. The different conversion factors apply to different reference preparations. There is not a many-to-one mapping here. As far as which standard is current: there is only one current international standard, IS 84/500. Its conversion ratio, like other reference preparations, is determined by the ratio of mass:activity of the reference preparation in an ampoule. StructureWiki (talk) 00:45, 23 March 2011 (UTC)[reply]

I am not opposed to adding in the measurements from PMID 18719199 in IUs next to the measurements in g; after all, additional information causes no harm. However, I see no contradiction in ranges as Richiez has stated (the purpose of the graph is to illustrate the normal variation across probands, after all). Given all the trouble that we've gone through just to understand the meaning of measurements of prolactin in IUs, it is unrealistic to think that measurements in IUs alone will be meaningful to the general public. This is why I performed the conversions. It is also not surprising to find out that the WHO recognizes these problems with the IU system, and in fact prefers a migration over to mass or molar units (from PMID 1477965):

Another important consideration is that of longterm consistency of unitage across reference materials. The World Health Organization (WHO) has stated that hormone measurements should eventually be expressed in mass or molar units instead of the arbitrary International Unit (IU) notation. The problem with the definition of concentration based on IU is that it is operationally defined by the choice of calibrator and assay, both of which lack precise specifications. Another complicating factor is that, due to short supply of the reference material, each laboratory or kit manufacturer has to use secondary standards that have been calibrated against the reference material. If these secondary standards differ in composition from the reference material, then assays using them will give differing results according to the specificity of the antiserum used.

StructureWiki (talk) 20:59, 22 March 2011 (UTC)[reply]

The contradiction in values is mainly for females, the immulite "data sheet" has a median value of either 12 or 13 while Beltran reports much smaller values. Btw nice quote above, perhaps could included into the text to alert readers about the mess. Richiez (talk) 22:30, 22 March 2011 (UTC)[reply]
This is not a contradiction. The values are in range, and the sample set is small (n=50); statistically, this sort of thing is expected to happen. StructureWiki (talk) 00:45, 23 March 2011 (UTC)[reply]
I agree that it's good mentioning the statement that mass or molar units should be used instead. Mikael Häggström (talk) 05:18, 23 March 2011 (UTC)[reply]

Daily variation of prolactin[edit]

The Segmented Sleep article http://en.wikipedia.org/wiki/Segmented_sleep mentions a daily variation in the amount of prolactin, but neither it nor this article gives any feeling for how broad the variation is. That would be an interesting point to compare with the Reference Ranges... — Preceding unsigned comment added by 160.83.42.136 (talk) 11:53, 12 January 2012 (UTC)[reply]

Segmented sleep is talking about brain levels of prolactin and is in desperate need for some citations, the prolactin article is in no way in a shape to start worrying about levels of prolactin in the brain. As of blood levels, the typical night max/day min ration might be 1.5-4. Richiez (talk) 20:32, 12 January 2012 (UTC)[reply]

Review[edit]

doi:10.1210/er.2011-1040 (Endocr Rev) might be useful at some point. JFW | T@lk 12:27, 8 August 2012 (UTC)[reply]

no citation for mental health effects[edit]

the article mentions the possibility of mental health effects due to hyperprolactinemia. i suggest finding some citations. such as: http://www.ncbi.nlm.nih.gov/pubmed/23590895 and more would be a good idea. — Preceding unsigned comment added by 159.238.36.19 (talk) 21:48, 6 December 2013 (UTC)[reply]

Effects[edit]

i'm not a med person, so this isn't about any of the medical aspects presented here. however, the use of the term "maternal organism" i find very strange. is this common usage for wikipedia physiology pages? if so, i've not noticed it anywhere else. and are males who have bred also called "paternal organisms"? if the term is common in medical discussions, it seems one vocal and politically active segment of western society would find it a godsend (pardon the pun). perhaps the problem is that this section (maybe the whole page) does not clearly state when it is discussing humans, and when it is discussing non-human mammals, and when it is discussing both? i assumed the "Effects" section was about human prolactin, not only because it wasn't clearly noted that it WASN'T, but also because of the use of the terms "babies," "women," "men," and "humans" within the section. granted, non-human mammalian young are sometimes called "babies," although not usually in...scholarly texts. let's see...from the wiki page on Cattle--"The gestation period for a cow is about nine months long. A newborn baby's size can vary among breeds, but a typical baby typically weighs 25 to 45 kg (55 to 99 lb)." from the wiki page on Pig--"Some attacks on newborn babies are non-fatal. Others may cause the death of the babies and sometimes, the mother may eat the babies. It is estimated that 50% of baby fatalities are due to the mother attacking, or unintentionally crushing, the newborn pre-weaned babies." well, maybe i'm wrong on that count.Colbey84 (talk) 08:46, 26 July 2015 (UTC)[reply]

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