Talk:Insulin

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Contents

[edit] Release of Insulin; ATP Dependant Potassium Channel

Please note that the picture detailing the release of Potassium is incorrect. It indicates the flow of Potassium ions in the wrong direction.

The potassium channel allows efflux (outward flow) of Potassium from the cell and into the extracellular space. Thus positive charges are normally leaving the cell thereby maintaining a negative membrane potential. In the presence of ATP this channel is blocked and the positively charged Potassium ions build up in the cell making the membrane less negative (depolarisation).

[edit] loss of important info

Thanks you for your editing and refractoring but please don't remove some important data.
Islets of Langerhans is historically a earlier term some authorities advise using "pancreatic islets" term now.
The same applies to naming convention of cells found in islets of Langerhans

  • B cells produce insulin
  • A cells produce glucagone and so on

Please be more cautious in your refractoring.

[edit] should be insulin not glucose

Under Intracellular transformation of the insulin signal it says This channel is under the glucose's control. Should it not be "this channel is under insulin's control?

[edit] stucture determination wording

The exact structure of insulin was established by a British molecular biologist Frederick Sanger. It was the first protein whose structure was completely determined. For this discovery he was awarded a Nobel Prize in Chemistry in 1958. Does this refer to primary structure, i.e. amino acid sequence?Habj 00:00 6 Jul 2003 (UTC)

I suppose so. Kpjas

I see some inconsistency:

Its chemical structure? was determined by Dorothy Crowfoot Hodgkin in 1967.
The exact structure of insulin was established by a British molecular biologist Frederick Sanger. It was the first protein whose structure was completely determined. For this discovery he was awarded a Nobel Prize in Chemistry in 1958


Kpjas 06:44, 14 Aug 2003 (UTC)

Should be more like:

Dorothy Crowfoot Hodgkin took the first x-ray diffraction photographs of insulin in 1935, and it took her 34 years to translate the crystalline structure determined from the x-ray diffraction pattern into a molecular structure. The structure of 2Zn insulin was reported by Dorothy and her coworkers in August 1969. Chinese crystallographers, led by Tang You Chi, also worked on the crystal structure of insulin, and Dorothy traveled to China to compare the electron density maps of the two structure determinations. The diffraction patterns for insulin extended to very high resolution. After her retirement Dorothy, with Guy Dodson and his colleagues, published a definitive monograph on insulin.

Frederick Sanger was awarded the Nobel Prize for Chemistry in 1958 for his determination of the structure of the insulin molecule.

He spent 10 years investigating the structure of the bovine insulin molecule, and by 1955 he had determined the exact order of all that molecule's amino acids. His achievement, in which the structure of a relatively complex protein was completely established, was an essential preliminary to the laboratory synthesis of insulin. The laboratory techniques that he developed for determining the order in which amino acids are linked in proteins opened the way toward the determination of the structure of many other complex proteins.

Thus Frederick Sanger determined the secquence of the amino acids of the protein "insulin" (the so-called "tertiary structure", but is was Dorothy Crowfoot Hodgkin who determined its "quaternary structure", i.e., the way the protein folded up on itself and formed intra-molecular connections with cystine bonds. ....

At least, that sounds not at all contratradictory to me. -- Someone else 07:03, 14 Aug 2003 (UTC)

True.
However, something needs clarification.
Not being a biochemist my understanding might be rather naive but to me chemical structure is primary through quaternary structures combined so both Sanger and Hodgkin researched chemical structure of insulin although slightly different aspects of it and on different levels.


The exact sequence of amino acids comprising insulin molecule was established by a British molecular biologist Frederick Sanger. His work was followed by Dorothy Crowfoot Hodgkin in 1967 who determined spatial conformation of the molecule, so called quaternary structure.

How about that?
Kpjas 20:42, 14 Aug 2003 (UTC)

Looks good, I've altered it a bit and put it in the article. Edit away!<G> -- Someone else 04:08, 15 Aug 2003 (UTC)

Amino acid sequence equals the primary structure of a protein, not tertiary. The three-dimensional structure in space is depending both on tertiary and quarternary structure. In this context, I think it is confusing to try and distinguish between the two. I removed that from the article. Habj 05:57, 17 Aug 2003 (UTC)

[edit] inapposite phrase, implies alligators?

Moved from the Insulin page:

If insufficiently low to produce death, hypoglycemia typically produces any of a variety of symptoms, many of which can indirectly cause death through accident or increased vulnerability to, for instance, predators.

Someone apparently refers here to hypoglycemia in animals ? Or humans strolling somewhere in Everglades ?
I think we can safely get rid of this speculative remark.
Kpjas 20:56, 16 Aug 2003 (UTC)

It is not one C-peptide for two insulin molecules. One C-peptide for two polypeptide chains, that will bind to each other with sulphur bridges and form one molecule... I changed that part. Habj 00:52, 28 Mar 2004 (UTC)

[edit] Paulescu not discoverer

Nicolae Paulescu is not the "discoverer of insulin". He is simply one of many researchers who were able to make weak extracts from dogs and slightly reduce blood sugar levels, something that other teams had been doing for 15 years at that point.

From http://nobelprize.org/medicine/articles/lindsten/index.html I quote: "As already mentioned the Nobel Prize to Banting and Macleod has been questioned ever since it was announced. [..] Others are of the opinion that Nicolas C. Paulescu, Joseph von Mering and Oskar Minkowski would have been as worthy, perhaps worthier, Laureates for this prize (e.g. Luft, 1971). [..]Paulescu was never nominated [..] according to the statutes of the Nobel Foundation, none of these candidates could have received the prize in 1923." True, without being nominated you cannot win the Nobel Prize. But just because someone is not nominated, it doesn't mean that someone doesn't deserve the prize. Before making bold statements, be sure you know what you're talking about! -- 195.37.184.165, 11:30, 30 May GMT+1)


Moreover the claim that Banting and Best were repeating his work is also false. Banting's "idea" was unique, and predates Paulescu's publications. It appears this claim was invented by Paulescu himself, who wrote to Banting after their publication, enclosing a copy of his paper which he assumes (incorrectly) he had read (see the UofT archives).

The history is clear: it was Banting's idea that lead to usable quantities of insulin, Collip's work that made it pure enough to test in humans, and Connaught and Eli Lily who made it into a practical product.

Maury 02:02, 4 May 2004 (UTC)

[edit] Banting's version of it is also wrong

Actually the history that is clear to most people in the world is also wrong. Amazingly, Banting's ligation idea does not lead to usable quantities of insulin. His dog longevity experiments were equivocal, because it was never conclusively established that their pancreases had been completely removed. These experiments did establish, somewhat more conclusively than previous teams, that pancreas extracts do reduce blood sugar. Then Banting, Best, MacLeod, and Collip worked as a team to produce usable insulin.

The history of the discovery of insulin was distorted by Banting's unaccountable hatred of MacLeod and violent suspicion of Collip. (He eventually reconciled with Collip.) The real story is properly explained in the excellent book by Michael Bliss, The Discovery of Insulin. Someone should revise the historical section after reading this book. That someone could be me, if I find time; but an interested doctor or medical researcher would be a better choice.

--Greg Kuperberg 04:01, 24 Nov 2004 (UTC)

[edit] insulin controls fat <---> glucose conversions. What?

The claim is made here that insulin causes uptake of glucose by fat tissue, conversion to fatty acids (or perhaps triglycerides?) in the fat cell and absence of insulin the reverse. Is this actually so? It is my understanding that only the glycerol backbone of a triglyceride is convertible back and forth to glucose and that the fatty acid side chains are not. Some clarity needs to be injected here I think. ww 17:22, 24 Jun 2004 (UTC)

No, but hepatic glucose production is mediated by insulin, and is increased in insulin resistance. This happens from lactate but also from free fatty acids. JFW | T@lk 17:06, 26 Aug 2004 (UTC)
jfdw, Hepatic glucose production from glycogen (ie, 'pre-stored' glucose) is indeed controlled by insulin levels as you note. And, intracellular absence of glucose eventually forces new glucose production from some of the amino acids (leading to the wasting appearance in untreated DM). But my question had more to do with sources of glucose, not mobilization from existing (once actual glucose) stores. Is there path between (or even one way) fat (ie fatty acids in one form or another) and glucose? ww 16:49, 30 Aug 2004 (UTC)
Yes. JFW | T@lk 12:11, 31 Aug 2004 (UTC)
Ah. Thank you. But what is the path? I have been told by a biochemist that only the glycogen backbone in trigliceryde fats is convertible to glucose. Still caught in the maze... ww 20:28, 8 Sep 2004 (UTC)
I cannot claim that, like an elephant, I have remembered this exchange. Indeed I lose things regularly, often finding them in plain sight after a search. But, I did stumble across this, and having found a part of the answer sometime ago (well an authoritative answer, anyway), thought I'd toss it into the mix here. Plants have enzymatic machinery to convert fatty acids to glucose, but animals do not. Geoffrey Copper, The Cell, 1997, ASM Press, Washington DC, Chap 2: Biosynthesis of Cell Constituents, pg 71. ww 04:45, 19 July 2006 (UTC)

[edit] material on Jones from the news dubious

A recent edit reflecting news reports about Marion Jones' alleged use of insulin implies insulin is (or acts like) a steroid or can be used an 'energizer'. This is an unfortunate addition and I will remove it soon if some support for the underlying physiological claims is not adduced. News reports are a poor source of information for the uses of any drug and insulin is one whose misuse is easily fatal. Whatever Ms Jones ex husband may (or may not) have said, misleading information on this hormone and its use should not be here, and probably not on WP anywhere. ww 15:39, 24 Jul 2004 (UTC)

I suggest this paragraph is axed if no source can be attributed. JFW | T@lk

Note that the first paragraph of the article mentions that insulin has anabolic properties. It's not at all unlikely that athletes could try to use it to enhance performance. Anabolic, when used in this tchnical sense, is not the same as the sense used by athletes and bodybuilders looking for an 'assist'. Their sense of the word is much less precise. The conflict in meaning is superficial. ww 22:17, 1 Nov 2004 (UTC)

Insulin does have signifigant performance enhancing effects. While no one should use it in this way, it is incorrect to say that it has no performance enhancing effects. (I came to this page when researching the use of insulin by bodybuilders)
". Extreme hyperinsulinemia strongly reversed postabsorptive muscle's phenylalanine balance from a net release to an uptake (P < 0.001). This marked anabolic effect resulted from a dramatic stimulation of protein synthesis (P < 0.01) and a modest decline in protein degradation. Furthermore, this effect was seen even when basal arterial or venous aminoacidemia was maintained. With marked hyperinsulinemia, protein synthesis increased further when plasma AA concentrations were also increased (P < 0.05)"-http://ajpendo.physiology.org/cgi/content/full/274/6/E1067
"stimulation of bulk protein synthesis during hyperinsulinaemia is observed only when concomitant hyperaminoacidaemia occurs" - http://bjsm.bmjjournals.com/cgi/content/full/37/4/356
"Another thing that the pros are doing is insulin after they are done training. The concept is to break the muscle down and then force glycogen into the muscle immediately after training with the use of insulin. Insulin is the most anabolic hormone known to man and it is one of the most dangerous. I've known many bodybuilders that have taken insulin after training and then not eaten enough carbohydrates to cover the insulin. This causes severe nausea and your blood sugar will drop rapidly. The result is a very sick person, until he gets some simple sugars into his s ystem. " - http://umanitoba.fitdv.com/new/articles/article.html?artid=75
anon poster: It is certainly true that insulin increases amino acid uptake into cells, including muscle cells. It also has a large variety of effects on other body systems, including vascular dilation and thus to some extent (via blood pressure) on heart action -- aside from direct effects on heart muscles cells. It also forces electrolyte movement into / out of cells generally. And the business with glucose control. And so on. This consellation of effects makes it a very poor choice for one looking to get buffed. The buffed side of things is not controllable by any availalbe mechanism -- thus if my own response to insulin is strong in regard to glucose level reduction, while not so strong in forcing amino acid uptake, I could go severly hypoglycemic (a very dangerous condition) before enough amino acids are uptaken to make a significant buff improvement. Whilst you, with different intrinsic responses might end up with a good bit more uptaken amino acids before your glucose drops to dangerous levels. I have heard absolutely no information on investigating these issues, much less recommendations to do so before undertaking insulin administration as an anabolic (getting buffed) approach. For, I suspect, the usual commercial / marketing reasons. Adn I include here the marketing of illegal materials (insulin in many places is prescription only), and incautious suggested actions (even where some insulins are available without prescription, their dangerour qualities require that a sane approach include MD or PA involvement).
Russian roulette (revolvers with one or several empty chambers and then daring the fates) is not a very sensible method of gambling, and insulin use in the absence of diabetes or some other medical indiccation is also not very sensible. Insulin use is not a 'simple issue', even more so than most medications. The central metabolism controls in any individual mammal (and fish and nematode worms as well, including most everything in between) is tremendously important to life and derangement can lead, easily, to brain damage or death. Without much more information about your particular biochemistry (due to genetic, environmental, deveopmental, and ... factors) you will not be able to use insulin without running large risks. Since, at present, no one on the planet -- including the most advanced research labs -- can so characterize your biochemistry, at any cost, best to stay away from insulin.
As for the implication in one of the extracts above, that some carbs or a little sugar is adequate protection against the dangerous hypoglycemic effect of improperly administered insulin, this is baldly true. HOWEVER, in a normal non-diabetic person, large enough amounts of insulin to cause hypoglycemia will also have other systemic effects (see above and the article) which will not be relieved by sugar (or carbs) ingestion. In any case, the time between ingestion and absorption into the bloodstream varies (substantially) with what else was eaten, current exercise / relaxation state (the digestive tract is substantially more able to process food under some conditions), and even the blood glucose level itself (most food processing and absorption requires energy, ie glucose). So even that 'solution' to too much insulin is more than a bit dubious in the real world.
Finally, let me point out that many people, including the 'pros', do a number of things for various reasons. Recall that pro motorcycle daredevils have done things like jumping large river canyons (eg, Evil Kneivel); this is not, in my view, reason for those not in the business and willing to accept the damage or death which has a high liklihood of resulting, for doing the same. That other folks do such things is not, in itself, a recommendation for others to do the same. Every individual should be sufficiently informed, really informed not merely repeating the opinions of others, before evaluating whether to attempt such things.
Exercise is a built-in mechanism which increases muscle mass, strength, endurance, etc. Inherent differences between individual biochemistries mean that an idividual's response to a given amount of exercise is to some extent inherent and, at our present state of ignorance (quite substantial), cannot be changed. Arnold had, during his competition days, not only a single-minded determination to do <whatever> he had to do to win, but also a biochemistry which responded rather more than most to the exercise it was (and remains) possible to cram into a single day. And of course to whatever else he did. In this, he and the other champion bodybuilders was favored by Fortuna (or pick your own term for fate). People do differ, and have always done so it appears. There are no magic pills or procedures for removing or changing nearly all of those differences.
My recommendation for this article, and any similar one, is that WP remain very wary of suggesting in any way that a dangerous drug, in this case insulin, can be used safely by non-experts when not medically indicated.
--ww 16:38, 1 August 2005 (UTC)
I just noticed this bit of this article in the process of some of my own research. While I do agree with everything you (ww) have said above, I have to point out that you have not actually addressed the anonymous poster's point, which is that the current wording of the article is factually wrong. It states that there is no evidence that insulin can have muscle-enhancing benefits for non-diabetics, which is, from what I can determine, wrong. Insulin combined with exercise has been shown in at least one study to produce significant improvements in muscle protein synthesis over either alone [1] (and I haven't yet found much to suggest this study was wrong in its conclusions), and as mentioned it can also have an effect on glycogen replenishment. The fact that athletes attempting to use it this way would be dangerous and difficult for a variety of other reasons does not change the effects that it does have in some situations. You seem to be arguing that because using insulin to promote muscle growth shouldn't be done (which it shouldn't), we should instead be telling people that it can't be done, but that really amounts to distorting the facts to promote an agenda (should the WP articles on cocaine or LSD attempt to say that they have no effect on users in order to discourage people trying them?). The correct encyclopedic procedure here, in my opinion, is instead to detail the evidence on what insulin has and has not been shown to do in this area (including the above information and references), and then explain (as you did above) why, regardless of this, it is a dangerous and generally inappropriate tool for such ends. Stating that there is no evidence, however, is wrong. --Foogod 00:35, 7 July 2006 (UTC)

[edit] hypoglycemia

I twiddled a bit with the hypoglycemia paragraph. As far as I know, abuse or overdose of thiazolidinediones does not directly lead to hypoglycemia. (Troglitazone has been withdrawn, but was still mentioned in the article!) I removed this as a cause for hypoglycemia. It is possible that someone on both insulinotherapy and glitazones gets hypos easier, because the insulin resistance is improving! This is not a direct effect of the thiazolidinedione. JFW | T@lk 17:06, 26 Aug 2004 (UTC)

PS does someone have an image on the second messenger system linked to the insulin receptor?

There should be a mention of reactive hypoglycemia as as alternative cause of low blood sugar as opposed to mismanagment and insulinoma. Waifwaller 04:22, 21 February 2006 (UTC)

[edit] human synthesized insulin

The article mentions this, but doesn't seem to point out how much it's taken over almost completely, and how those wishing/needing animal-based insulin find it difficult/impossible to get what they need as a result. This is a story about the subject. I haven't changed it yet, since I'm not sure where to put it in. --rob 09:01, 3 August 2005 (UTC)

[edit] probably vandalism of a sort

I don't have time to fix it, the last edit removed some brief biochemisty (about 75 words in separate paragraphs) and all the links including to other language WP.

The previous edit seems to have been NPOV on the question of the striking similarity of insulin from animals as diverse as C elegans, fish, pigs, cows, and humans. I appreciate the intensity of feeling on this issue, but it does not (should not extend to censorship of facts, and striking ones at that). This is also relevant to research a C elegans insulin pathway has now been fully elicidated as to production and interanl cell funtions and control. This is an extraordinary result by any standard regardless of politics faith or lack of either.

Bothe these points deserve attention from some one with the time. The last paragraph might link to the list of diabetics somewhere on WP (several of these folks are indeed athletes). The paragaph was there as a kink of alrt ot dangerous potions offered by shady lockerroom chemists.

ww 01:48, 26 September 2005 (UTC)

[edit] Non-beta cell research

Just added two quick sentences to point out the research being done on increasing secretion efficiency in transfected non-beta cells. I think it is an important point as engineering of non-beta cells likely is a less expensive alternative to beta cell transplantation, assuming the secretion efficiency problems can be worked out.

CLGroup1 01:55, 4 January 2006 (UTC)

[edit] Drinkable insulin breakthrough

"INSULIN injections could become history for millions of diabetics, thanks to a breakthrough by Scottish chemists. A drinkable insulin has been developed, spelling an end to the four jabs a day that many patients have to endure." http://thescotsman.scotsman.com/index.cfm?id=457812002

I don't know - found this through google. It is dated Mon 29 Apr 2002, but I can't find anything recent on this. Anyone else heard/knows of this? If so maybe add to the article?

User:Valerij 09:45, 21 January 2006 (UTC)

[edit] Growth hormone is catabolic?

I am assuming that there has been a mistake in the statement below claiming that growth hormone is catabolic. As its name implies, I believe that growth hormone falls into the category of an anabolic hormone.

There are two groups of mutually antagonistic metabolic hormones affecting blood glucose levels:

  • catabolic hormones (such as glucagon, growth hormone, and catecholamines), which increase blood glucose
  • and one anabolic hormone (insulin), which decreases blood glucose

Anon: I was about to make the same point - growth hormone is anabolic, cortisol might be a better example of a catabolic hormone in this context since it is an insulin antagonist (Freeman, 2002).

[edit] Replace empirical formula with molecular weight?

I don't know why people quote the empirical formula for macromolecules, it's not useful for anybody. On the other hand, the molecular weight is one of the most important facts about a protein from a biochemist's view.

I changed it, since nobody seemed to object.
While I agree that MW is more useful for researchers, this article is not written for them. I see no reason why the choice is one or the other. Both would be appropriate, though as you susggest the empirical formula is less than useful in research. Average Readers might find it interesting that there are so many sulphur atoms and so on.
I would be good to sign your comments (with four "~" in a row), so edits retain some connection with editors. Thus, ww 19:53, 23 April 2006 (UTC)
Sorry, I'm a wiki newbie. As far as I have noticed, the only reaction of average readers to one of those giant empirical formulas is "Oh, those wacky chemists" and "I'll never understand that stuff". I think it's unfair because, as I said, not even scientists can use them. Oszillodrom 12:03, 25 April 2006 (UTC)oszillodrom
Have only just noticed this reply. Well, ... I can appreciate that you have observed this among those you know, but there are quite a few others who might not be so uninterested. I suggest it be restored as the cost is some few bytes in a database and a bit of space on a display or in a printout. Parsimony is certainly a sensible attitude, but it can be overdone, as I think in this case. ww 19:36, 23 June 2006 (UTC)
I realize this in an "old" isssue, but as a biochemist the empirical formula is really meaningless. It provides no useful information other than by looking at it I could guess it was for a protein - I say get rid of it since it only confuses those who don't know enough chemistry. Hichris 21:32, 12 October 2006 (UTC)

[edit] 'diabetic' = derogatory term, reflected in recent edits

I'm afraid that I cannot agree this is a sufficiently momentous issue as to justofy the extensive edits princessLJ has made. It is alleged by some that the word 'diabetic' is prejudical and derogatory. And they usually suggest that 'people with diabetes' is acceptable in contrast. As the underlying situation is not changed by adoption of a different word or phrase, substitution for a long accepted (and still widely accepted) term is surplusage. I will revert this flavor of political correctness shortly unless there's some supportive comment here. ww 19:36, 23 June 2006 (UTC)

I'd like to begin by apologizing if this is not the apropriate place/manner for responding to your comment(s). I am realatively new to Wikipedia and I am still learning some of the subtle differences. I also would like to apologize if you took my actions as something intended to offend...that was most certanly not my intent. Though I did make some extensive edits this morning, I was not intending to suggest that you or anyone else was trying to be, "prejudical and derogatory".
No apology is necessary. There are some conventions and policies which can be chased down on the community pages (see community portal to the left). The point of it all is to produce the best reference work possible not to do things the 'right' way. If we could all do that by standing on our heads and chanting WP, WP, ... I suppose that would be favored as appropriate. Till that time, the conventions which have developed have been quite successful. You might want to contribute an addition on such points as this, if you wish. See the Talk pages for the relevant community policy. ww
The word "diabetic" is an adjetive to describe things that relate to diabetes. Over time its common use has morphed into a noun that means "a person who has diabetes". The general consensus of most people in the medical and professional community, in addition to many people with diabetes, is that when "diabetic" is used as a noun, it is inapropriate because it defines the individual by his/her disease. (I recognize that not all people with diabetes and medical professionals feel this way, but most do) For example a patient with cancer is not called a "Cancer-ic" or a person with lupus "Lupic". There are other diseases, asthma and epilepsy for example, that have experienced a similar phenomenon with the adjetive morphing into a noun, and the community that relate to those diseases are expeiencing similar discussions nationwide.
Again, I am still learning about Wikipedia and its proper etiquette so please let me know if I have done anything wrong so that I can learn. --04:07, 24 June 2006 (UTC)Princess LJ
I've taken the opportunity to preface your reply with ":" as is the more or less accepted convention for keeping comments visually distinct on talk pages (this para begins with "::"). The claim you make, that '...most do' is just the politically correct viewpoint to which I had reference. The English language, and its word formation, is not uniform nor parallel in analagous meaning situations, so the absence of the nouns 'lupic' or 'canceric' imputes nothing either way about the acceptibility of 'diabetic' as a noun. 'Diabetic' is actually commonly used as a noun, as is asthmatic. WP is not the place to enforce one alternative usage viewpoint versus another, nor to attempt to correct common usage. If its use is offensive, as indeed some claim just as you suggest, WP is not the venue in which to repair the offense. Perhaps you could add a paragraph discussing the dispute, hopefully with some references readers could chase down. I'll revert the changes. ww 23:24, 24 June 2006 (UTC)

[edit] Empirical formula of insulin

Following on from the discussion above, I went to the article to see what the empirical formula of insulin is, and found it wasn't there! Some people are indeed interested in this, or at the very least the chemistry of the molecule (as opposed to the biochemical language). Can anyone help? Carcharoth 23:58, 28 June 2006 (UTC)

It's available in an earlier version of the article, accessible from the history tab at the top of the page. Or in several references. Be bold and dive in. ww 05:03, 6 July 2006 (UTC)
From the dates of the above discussion (Empirical...), somewhere in April or June... Carcharoth 16:10, 11 July 2006 (UTC)
Ah. that was quick. Carcharoth 16:11, 11 July 2006 (UTC)

OK, retrieved from the page history, and checked elsewhere, empirical formula is: C257H383N65O77S6. Now, I think that both "molecular weight" and "empirical formula" are equally useless factoids to the average reader, unless it is explained why it is relevant. So I am going to be bold and put the empirical formula AND the molecular weight in there. It would be nice to have this sort of thing in an infobox as well, though... Carcharoth 16:16, 11 July 2006 (UTC)

[edit] featured article nomination? comment invited

Having watched for some time, I think this article is ripe for featured article status. Let's have a few comments on this, and see if we can do it. ww 05:03, 6 July 2006 (UTC)

I note the dead silence, which invites me to impute to that silence assent, as Sir Thomas More suggested must be construed from his silenc on the question of the King's divorce and with regard to Papal supremacy, and Parliamentary lack of authority and jurisdiction. Lest your silence be misconstrued, please weigh in on this. Eh? ww 21:15, 20 July 2006 (UTC)

[edit] Discrepancy for bovine insulin

Quoting from the article:

1) "Amongst vertebrates, insulin has been highly conserved. Bovine insulin differs from human insulin in only three amino acid residues, and porcine insulin in one residue. Even insulin from some species of fish is also close enough to human insulin to be effective in humans."

2)"The initial source of insulin for clinical use in humans was from cows, pigs or fish pancreases. Insulin from these sources are effective in humans as they are nearly identical to human insulin (two amino acid difference for bovine insulin, one amino acid difference for porcine). Insulin is obviously a protein which has been very strongly conserved across evolutionary time."

So does bovine insulin differ by 2 or 3 amino acids, and what is this "amino acid residue" thing? Carcharoth 16:56, 11 July 2006 (UTC)

(A) From gsu.edu: "There are only three differences between bovine insulin and human insulin. These differences occur at position 8 on the alpha chain, 10 on the alpha chain, and 30 on the beta chain. On the human insulin, threonine replaces the alanine in position 8. Isoleucine replaces valine in position 10, and threonine replaces valine in position 30." (B) From Amino acid: "An amino acid residue is what is left of an amino acid once a molecule of water has been lost (an H+ from the nitrogenous side and an OH- from the carboxylic side) in the formation of a peptide bond." Hope this helps. --Arcadian 19:42, 11 July 2006 (UTC)
That's great, thanks. BTW, shouldn't the article be corrected? I would do it myself, but I thought maybe there was some reason why you haven't done so. Is the article correct to say that there is a "two amino acid difference"? Carcharoth 20:55, 11 July 2006 (UTC)
I have now corrected the article. Thanks for catching the discrepancy. --Arcadian 02:43, 12 July 2006 (UTC)

[edit] removal of obscure point

I have removed a commenbt about atheletes using insulin to restore nutients in their cells as, if it's not repetitive of earlier material, is incoherent is saying something other than it does so work. If anyone want it to stay, let's figure out what was meant before trying to reinstate it? ww 21:11, 20 July 2006 (UTC)

Probably referring to it's use to increase muscle mass by the exploiting the actions described in the section "Actions at a cellular level". This makes insulin a popular, albeit dangerous, practice amongst advanced bodybuilders whose lean mass gain have stopped, even with large doses of androgenic/anabolic steroids.

[edit] Protbox

I would like to add a protbox to this article. The protbox is the infobox for proteins (a more detailed form of the protein infobox). It is part of the WikiProject Molecular and Cellular Biology. One of the goals of the project is to install a protbox or a protein box on all protein articles. This article is very well established and I don't want to upset anyone who has put a great deal of work in it. I have already created it and it can be found here. I think it would make a good addition, since it summarizes much of the information related to Insulin. If you think it can be utilized feel free to do add it or comment on your support or opposition. --GAThrawn22 00:14, 22 July 2006 (UTC)

I think it can be used. However the linked item is problematic in several respects. The ones I've noticed include:
there are many more pharma insulins and some are not precisely insulin but analogs to permit particular patterns of action;
cell type should be more specific -- beta cells of pancreatic Islets of Langerhans;
proinsulin is another, related compound, not insulin;
taxa expressing include everything between nematode worms (c elegans) through fish, cats, dogs, and humans;
the hexamer illustration is striking but not obviously related to insulin the cellular absorption regulator, some explanation is needed, perhaps in the image caption.
But on the whole I think it's a good idea. Others' thoughts? ww 02:29, 22 July 2006 (UTC)
Your suggestions are great. You are free to change any field if you feel that it's inadequate or incorrect. The protbox also contains information about the gene that codes for the protein and that's why proinsulin is in the listing for alternate names. Since there aren't any objections I am going to include it in the article. I just haven't figured out how to rearrange the existing pictures to accomodate the protbox. --GAThrawn22 18:08, 26 July 2006 (UTC)

[edit] Growth Hormone Catabolic Hormone?

There are two types of mutually antagonistic metabolic hormones affecting blood glucose levels:

   catabolic hormones (such as glucagon, growth hormone, and catecholamines), which increase blood glucose
   and one anabolic hormone (insulin), which decreases blood glucose

Is that actually true? Isn't GH anabolic?

[edit] Insulin as a medication/Principles/"..strongly conserved across evolutionary time."

Sorry for not discussing this edit beforehand to explain (not to mention editing the first time as a "Minor Edit," not understanding the significance): I just started trying my hand at editing articles and must plead ignorance concerning Wikipedia etiquette. Although I disagree with the inclusion of the topic of evolution in the article (as being neither germaine, nor factual, nor conforming to NPOV) I thought it better to try to balance this statement with (what I thought) a pretty harmless alternative concerning Intelligent Design (which also leaves out any overt religious assertions). Really, this sentence should be omitted entirely. Darentig 12:18, 23 August 2006 (UTC)

The question of evolution vs intelligent design is a controversial one, and, on WP, is best kept to the relevant articles and their talk pages. As WP is not devoted to 'truth' (no matter whose or Whose) but rather to reporting current understanding, any refernce to the simliarity of insulins from assorted species (across a huge range) in the context of insulin action in humans, is best accounted for (in passing as it is not the central subject of this article) by reference to an evident conservation of composition across all those species, done via pressures which would ordinarily have made changes. That was the import of the comment re conservation; it's a measure of the centrality and importance of the insulin / glucose metabolic control across essentially the entire animal world.
I personally would like to see an article on the similarities of emchanisms and structure across species, but can't suggest much save perhaps muscles and nerves which are very little different between, say, bees and dolphins. A fascinating issue, I think. It would take someone with D'Arcy Thompson's breath of knowledge and perspective to do, though.
How this conservation has been arranged for (if there is/are Arranger(s)) or came to be (if there are none, or if an existing one is content to use evolution / natural selection pressures / random mutations to achieve desired Ends) is another issue altogether. And is not invoked by noting the quite remarkable conservation of insulin's structure and function across so vast a range. I think therefore that your objection is misplaced, as stepping on a step not present.
In short, there's nothing un-WP about the phrase, and nothing NPOV about it either, at least in an article about insulin. In another, perhaps. So no need to change it.
As for apologies for not understanding how WP works, we've all been there. To your considerable credit, you are willing to discuss the issue (not true of a great many with strong views, religious or otherwise, and almost never true of the assorted vandals who regularly deface articles). You might want to look through the pages at the Community Portal (to the left on most screens) for the polices and conventions which have produced the WP we see today. Neutrality, no original research, cite your sources, be civil, no edit wars, take it to the talk page, ...
Welcome aboard. ww 14:08, 23 August 2006 (UTC)
I appreciate your gracious response concerning my apology, and my position.
I agree wholeheartedly that evolution vs intelligent design would be better served on it's own page. It is for this very reason that I contend that the reference to evolution should not be included in the article at all. It's inclusion needlessly introduces this controversy to the page, and, with it's current wording, assumes the evolutionary position (which is not neutral, and is also without citation I would note). This is why I had thought to balance the statement with a very brief reference to intelligent design, and persons who may be interested in following the "e vs id" debate could then do so in the appropriate articles (which does add some interest to the article, I think).
I also strongly agree with your point about, "the centrality and importance of the insulin / glucose metabolic control across essentially the entire animal world." This is indeed a fascinating fact, and one of which I would be in complete ignorance were it not for it's inclusion in this page, so I would certainly not want to see it struck from the article entirely.
If you so strongly object to the inclusion of intelligent design, perhaps a rephrasing would be in order? How about "Insulin is, therefore, a protein of central importance to metabolic control across the entire animal world."?
Also, I just noticed that the second sentence in this paragraph reads, "Insulin ... are effective ... they are nearly...," whereas it should read, "Insulin from these sources is effective in humans as it is nearly identical to human insulin (three amino acid difference for bovine insulin, one amino acid difference for porcine)."
Fascinating topic. Darentig 15:36, 23 August 2006 (UTC)
D, I really don't think that the mention of evolutionary time is taking a stance on one side of the e vs ID debate. It's a shorthand way to make the point about universality of the mechanism and so of its central importance. There's no bias on the controversy traveling with the phrase.
That said, if there's lots of concern about it, I suppose a rather wordier digression making the point about universality would do the same thing. Can't imagine that it would read well thouhg, and one of the WP goals (honored in the breach almost universally) is to end up with clear and concise (ie, quality) writing. In short, I think you're suggesting we start up a staircase that itn't there. ww 13:00, 24 August 2006 (UTC)
I guess it depends on what you mean by "mechanism." Do you mean the "universality of the (evolutionary) mechanism," or the "universality of the (insulin) mechanism"? If insulin, the point is well made already without any reference to evolutionary time, and needs no digression to accomplish, as I suggested in the replacement phrase, "Insulin is, therefore, a protein of central importance to metabolic control across the entire animal world."
Or look at it this way: If I had changed the sentence to say, "Insulin is obviously a protein which figured strongly at the creation," would the mention of creation be taking a stance?
Tell you what though: I'm not really willing to push the point (of evolution) to the (relational) point of risking hard feelings. If you feel that strongly about it, leave it as is. I certainly remember all too well when I felt that strongly about evolution too. And I probably wouldn't have seen it as making any kind of statement either! :-) Besides, people are always free to make the edit in their own minds.
Consider the issue closed then, for my part anyway.Darentig 14:29, 24 August 2006 (UTC)
D, Yes it was the universality of the insulin mechanism I think that will be seen here. And the use of evolutionary time is not necessarily an endoresement of evolution but a way ot talking about vey long time reaches.

[edit] phrasing revisions

Proceeded with the above grammatical revisions, and also revised "cows, pigs or fish pancreases." to "cow, pig or fish pancreases."
Changed the last sentence of paragraph 2 from, "Though insulin production from animal pancreases was widespread for decades, there are very few patients today relying on insulin from these sources." to "Insulin production from animal pancreases was widespread for decades, but there are very few patients today relying on insulin from these sources." This was just to make the language flow better as I thought the repetitive use of "though" in the previous sentence and then again in this sentence clumsy.
I also find this sentence, "Differences in suitability of beef, pork, or fish insulin preparations for particular patients have been primarily the result of preparation purity and of allergic reactions to assorted non-insulin substances remaining in those preparations." to be rather clumsy, but have not attempted a revision as I am not 100% sure of the author's intended point.
Am waiting to obtain some consensus as to the evolution statement. Darentig 12:48, 24 August 2006 (UTC)

[edit] someone want to fix and add back this confusing phrase?

I removed the parenthetical phrase from, "Insulin's concentration (more or less, presence or absence) has extremely widespread effects throughout the body."

I'm not sure what the author intended, but it was unclear as written. If someone knows what was intended, please clarify it and put it back.

I suspect it was not concentration per se which was meant here, but rather that insulin has a great many effects and that its concentration matters accordingly. I think I might add that diabetics, whose insulin levels are odd in one or more ways can have trouble because of these additional effects. Some of hte CHAOS sysmptoms are someimtes blamed on insulin (too high in the case of Type 2s). ww 16:14, 23 October 2006 (UTC)

Vandalism removed from "Discovery and characterization" section today.mildly_odd 23:24, 22 November 2006 (UTC)

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