Insulin



Insulin is a hormone produced by the pancreas (a gland that releases a digestive juice into the intestine). The pancreas is composed of acinar cells, which produce digestive enzymes, and the islet cells of Langerhans, which produce hormones.

What Insulin Does

Four hormones are produced by the Langerhans islet cells. Insulin is produced in the B cells, glucagon in the A cells, somatostatin in the D cells, and pancreatic polypeptide in the F cells. Insulin promotes anabolism (building up of tissues) and inhibits catabolism (breaking down of tissues) in muscle, liver, and fat cells. It increases the rate of synthesis (blending) of glycogen, fatty acids, and proteins. Lack of insulin causes diabetes mellitus (a disease characterized by excess sugar in the blood and other body fluids).

Insulin's most important feature is its ability to increase the rate of glucose (a crystalline sugar) absorption by cells. Glucose is the most efficient fuel used by and found in almost all cells. Insulin causes a decreased concentration of glucose in the blood and causes the cells to store glycogen (a starchlike substance), mostly in the liver. It also promotes the entry of other sugars and amino acids into the muscle and fat cells. Insulin is therefore responsible for promoting fat storage in fat cells and for the total quantity of protein in the body.

Insulin Production

Insulin production is stimulated by high levels of glucose and inhibited (limited) by lower levels of glucose. Insulin regulates glucose with glucagon. Glucagon catabolizes (changes into a product of simpler composition) glycogen to glucose and also raises the blood sugar. Glucagon can be given to increase the blood sugar when intravenous (by needle) glucose cannot be given. Glucagon takes about twenty minutes to raise the blood sugar. Intravenous glucose raises it instantaneously, which is why it is preferred in treatment. Together insulin and glucagon ensure that the body stores and maintains the proper level of glucose for its energy needs.

Diabetes

Diabetes is from the Greek word meaning "siphon," and "mellitus" comes from melliferous, meaning "of or relating to honey." Diabetes has been recognized for centuries and was originally diagnosed by tasting the urine and finding it sweet (melliferous). The high sugar also causes the kidneys to excrete (or siphon) large amounts of water. In 1815, French chemist Michel Eugene Chevreul discovered that the sweetness came from grape sugar or glucose. Later discoveries showed how the body makes, stores, and uses glucose.

Injury to the pancreas was linked to diabetes beginning in the seventeenth century and confirmed by animal experiments, particularly those of the German physiologist Joseph von Mehring (1849-1908) and a Russian pathologist, Oscar Minkowski (1858-1931). The acinus cells were found in the seventeenth century by the Dutch anatomist Regnier de Graaf and the islet cells in 1869 by a German pathologist Paul Langerhans (1847-1888).

Hormones

In 1905 English physiologists Ernest Starling and William Bayliss discovered hormones. Hormones are substances secreted (released) by glands and carried in the blood to control cell activity elsewhere. In 1916 an English physiologist named Edward Sharpey-Schafer proposed that a hormone produced by the pancreas lowered the level of glucose in the blood. He called the hormone "insuline," the Latin word for "island," because he believed it came from the islet cells of the pancreas.

The first drop of biosynthetic insulin, This synthetic product was made by Eli Lilly and Company using recombinant DNA technology.
The first drop of biosynthetic insulin, This synthetic product was made by Eli Lilly and Company using recombinant DNA technology.

Credit for discovering insulin is given to Canadian surgeon Frederick Grant Banting (1891-1941) and Canadian physiologist Charles Herbert Best (1899-1978). Banting and Scottish physiologist and professor John James Rikard Macleod (1876-1935) were jointly awarded the Nobel Prize for medicine in 1923. Banting gave half of his share to Best, and Macleod gave half of his share to James Bertram Collip, because of the men had contributed to the discovery.

The First Insulin Patient

Collip, a professor at the University of Alberta, had experience in the chemistry of hormones. Prior to January 1922, he had prepared an insulin pure enough to be used on human patients. The first patient to receive insulin was 14-year-old Leonard Thompson. Thompson was admitted to Toronto General Hospital with a high blood glucose level; he also was urinating between three and five liters of fluid per day. Despite his rigid diet of only 450 calories (the only known treatment at this time was a diet low in carbohydrates), Thompson continued to excrete (get rid of through bodily waste) large amounts of glucose. On January 11, 1922, he was given insulin. Within a fairly short time, his blood sugar level came down and he stopped urinating large amounts of liquid.

Humulin

In 1982 insulin became available as a genetically-engineered product called Humulin. Humulin's structure is identical with human insulin. The A and B chains are produced separately in different strains of E. coli bacteria. The E. coli have been genetically encoded to produce each of these strains. The strains are separated from the bacteria and purified. The purified chains are combined chemically and repurified.



User Contributions:

sushma parasd
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Mar 2, 2006 @ 4:04 am
Structure and function of insulin receptors.
Insulin binds to cells at specific protein sites called receptors. The insulin receptor consists of two alpha subunits and two beta subunits. The alpha subunits occupy the outer surface of the cell, whereas the beta subunits span the cell membrane and cell interior. The portion of the beta subunits occupying the cell interior are enzymes called protein tyrosine kinases. Isolation of the genetic material, deoxyribonucleic acid (DNA), that codes for the insulin receptor, has been useful in understanding the function and control of these protein tyrosine kinases. When insulin binds to the receptor, it activates the protein tyrosine kinase, which then adds phosphate groups to specific sites on the receptor, the tyrosine residues. This phosphorylation reaction may trigger the various actions of insulin on glucose metabolism. Although tyrosine kinase appears to be essential for insulin action, the mechanisms linking tyrosine kinase phosphorylation of the receptor to insulin effects remain unclear. Insulin receptor DNA has also been useful in identifying insulin receptors of other species such as the fruit fly. Future studies will focus on determining the substances controlled by the tyrosine kinases of the insulin receptor.
Sushma.Prasad Btech Bioinformatics
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Mar 2, 2006 @ 4:04 am
Insulin resistance
When your cells are exposed to insulin at all, they get a little bit more resistant to it. So the pancreas just puts out more insulin. Cells become insulin resistant because they are trying to protect themselves from the toxic effects of high insulin. They down-regulate their receptor activity and number of receptors so that they don't have to be subjected to all that stimuli all the time. When your cells are exposed to insulin at all, they get a little bit more resistant to it. So the pancreas just puts out more insulin. Cells become insulin resistant because they are trying to protect themselves from the toxic effects of high insulin. They down-regulate their receptor activity and number of receptors so that they don't have to be subjected to all that stimuli all the time. Different cells respond to insulin differently. Some cells are more resistant than others, as some cells are incapable of becoming very resistant. The liver becomes resistant first, followed by the muscle tissue and lastly the fats. As all these major tissues, become insulin resistant your pancreas is putting out more insulin to compensate. Any time your cell is exposed to insulin it is going to become more insulin resistant. That is inevitable, we cannot stop this process, but the rate we can control.
But the pancreas can't always keep up that high level of insulin production forever. Once the production of insulin starts slowing down, or the resistance goes up, then blood sugar goes up and the person becomes a diabetic.
"Insulin resistance syndrome" refers to a combination of risk factors for type 2 diabetes, including chronically elevated insulin levels, low HDL ("good") cholesterol, abdominal obesity and high blood pressure.
Excessive intake of all carbohydrates, especially the high-glycemic type, is the primary culprit in the development of insulin resistance.
Type 2 diabetes occurs when the body no longer responds to insulin. As a result, levels of insulin in the blood become elevated and over time, can raise the risk for kidney failure and blindness, as well as heart disease.
A recent study(4) has found that insulin resistance syndrome, or "syndrome X," is found in families with a history of early heart disease - a heart attack or blood vessel blockage before age 55 in men and before age 65 in women.
Marilyn Guest
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Apr 5, 2008 @ 7:07 am
Why is my pancreas producing less insulin. Is it my fault for eating a bad diet containing to much sugar. Can I fault this reduced production of insulin by a total diet change.
Please can you give me some advise. My GP wants me to start insulin. My medication at this time is AVANDAMET 2000mg/2mg per day GLIMEPRIDE 4mg
Lakeeya
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May 29, 2008 @ 9:21 pm
For your info related to insulin and it's production.
Sara
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Sep 18, 2008 @ 11:11 am
its a very usefull websire,,

i got some good information from it,,and iam sure it will help me with my studies

iam very intrested in studing about diabetes

thank you for th website

yours
sara
Nagesh
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Jul 3, 2009 @ 3:03 am
I require more information about Insulin production in molecular level
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Feb 25, 2010 @ 6:06 am
can you please tell us that how can the beta cells produce insulin and how the insulin enters into our blood streams?
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Apr 20, 2010 @ 10:22 pm
I am always looking for information. Just found out I am pre-diabetic. The sentence ASTOUNDED me..I am 53..somewhat fit..5'2", and weigh 115 lbs. I don't eat, crave sugars, except in my 2 cups of coffee 5 days a week, but am a MAJOR carb lover. Little history of diabetes in family, grandfather, aunt. So it just blew me away! I have had MAJOR high blood pressure issues since age 38. (still trying to contol those), with many, and different drugs~~sigh~~. I went though menopause at that age also..I believe there is a major connection! I was major active when younger,(into my late 30s)Burn out stopped me for a while, but last few years its a lot of pain issues to stop me from even just daily walks. I believe my way of life at this point could change where it goes!..diet/exercise/and way of life.
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Sep 15, 2010 @ 6:18 pm
I am a 51 year old type 1 diabetic. For the last several days, I've been having trouble keeping my blood sugar up. It usually does this for a day or two a month, but this has been going on for several days. I am not eating or exercising any different than I usually do. I'm not sick. My blood work a few months ago was all good. What causes this?
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Oct 11, 2010 @ 2:14 pm
I hope someone can answer this question...An insulinoma produces too much insulin, causing the body to go into hypoglycemia. Why isn't glucagon secreted to raise the blood glucose levels? If it is secreted, why does the body stay in a hypoglycemia mode for so long?
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Feb 15, 2011 @ 1:13 pm
Are there any natural supplements that a person can take that will help to stimulate the pancreas to produce insulin when the
patient gets older?
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Mar 23, 2011 @ 11:11 am
What can be done if the pancreas stop producing insulin.
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Mar 28, 2011 @ 10:22 pm
I'm 52 years young with out of control diabetes which I am working a little harder to bring under control. My question is as I get older will my body stopp producing insulin over time even if I do get it under control?
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May 1, 2011 @ 12:00 am
I was diagnosed as diabetic 1996. my sugar was all over the place. Four years ago I started Novalog 3 times a day and Levemir at hs.

I lost my 5th toe right foot. Then I lost my Great toe left foot in July 2010. Late October I had a silent heart attack. Worst in my opinion is the ever increasing neuropathy
both legs now up to mid Tibia and left hand. My Diabetes also block any pain when I had the heart attach and didn't feel any symtoms of the CVA Silent heart attach. Another bennefit of diabetes no chest pain.
My Cardiologist gave me a chemical treadmill and that is how we discovered the CVA.

I then put myself on a low 500 cal per day. I have not taken any insulin or oral medication for four months.
My beginnig weight was 290lbs in November 2010. Today I way 215. Aic 3 months ago was 6.0, and6.6 a month ago.
Thirty day average on my blood glucose 116. Do not try this without your Doctor knowledge . If your not the right patient,you can get sick and could DIE.
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Oct 23, 2011 @ 4:04 am
I am studying clinical nutrition in college.So I can answer some of these questions

#7asks:



There are no foods that generate insulin or any other hormone (chemical) that regulates your metabolism (Meta = change bol= growth ism + state of)You are alive because of your metabolism- which is fed energy by eating.The whole process is chemical which is why you asked this question!!
Yet it is a lot more complicated than just eating certain foods to produce insulin. Your body makes insulin unless you were born with a genetic defect that would make you a congenital diabetic TYPE1 ... I hear in your question that the disease /epidemic you are worried about is type 2 Diabetes . , you can read in the next post the answers to ,,Okay # 14 and #15 and # 17 Because part of your sloution is in their is answer...



Important Disclaimer:
No express or implied warranty (whether of merchantability, fitness for a particular purpose, or otherwise) or other guaranty is made as to the accuracy or completeness of any of the information or content contained in any of the pages in this web site or otherwise provided by personal training on the net, Margaret, the writer of this article , margothefoodie TM or this website. No responsibility is accepted and all responsibility is hereby disclaimed for any loss or damage suffered as a result of the use or misuse of any information or content or any reliance thereon. It is the responsibility of all users of this website to satisfy themselves as to the medical and physical condition of themselves and their clients in determining whether or not to use or adapt the information or content provided in each circumstance. Notwithstanding the medical or physical condition of each user, no responsibility or liability is accepted and all responsibility and liability is hereby disclaimed for any loss or damage suffered by any person as a result of the use or misuse of any of the information or content in this website, and any and all liability for incidental and consequential damages is hereby expressly excluded.
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Oct 23, 2011 @ 4:04 am
Okay # 14 and #15 and # 17 Because part of your solution is in their is answer...Pay attention #7
Part 1

Type 2 Diabetes and Pre-Diabetes
(yes that is a condition that can be detected if you fall within certain height to weight to fat- in -the -wrong places (including HIDDEN BELLY FAT) parameters Google diabetes risk test english pdf

What you need to know!

The red blood cells carry markers that indicate sugar levels, and a red blood cell lives for about 3 months.You can read how your average sugar level is with the A1C test. It is very accurate. With the A1c test where the window for detecting higher blood sugar levels is good for 3 months , your doctor or lab can tell you that you are headed or not headed for trouble. Your A1C level needs to be below 5.6 . Its important you get this test EVEN IF YOU ARE TESTING DAILY YOU NEED THE BIG PICTURE!

This reading along with a fasting glucose test with your checkup (because no kidding overnight your liver makes sugar from your stored fat - its part of a survival mechanism )tells the doctor when you are making too much sugar, for how long the sugar is too high and what your sugar level is before breakfast (Break the Fast) .

So ideally to keep the body from making No Use of the extra sugar overnight, and to keep the body from circulating Extra sugar (everything breaks down into sugar even meat)
You can modify your food intake with some professional help because it has to be based on your lab results.

What you can do now
However you can start spreading out your intake of Complex Carbohydrates i.e. an apple with the skin after a walk, munch a broccoli stalk with some nuts for a afternoon snack , and ride your bike home for dinner ( notice the combinations of protein fats carbohydrates and exercise) I try to get these combinations in my Pre- Diabetic clients (I am a personal trainer as well)

you know this is a long answer will post part 2 shortly


Important Disclaimer:
No express or implied warranty (whether of merchantability, fitness for a particular purpose, or otherwise) or other guaranty is made as to the accuracy or completeness of any of the information or content contained in any of the pages in this web site or otherwise provided by personal training on the net, Margaret, the writer of this article , margothefoodie TM or this website. No responsibility is accepted and all responsibility is hereby disclaimed for any loss or damage suffered as a result of the use or misuse of any information or content or any reliance thereon. It is the responsibility of all users of this website to satisfy themselves as to the medical and physical condition of themselves and their clients in determining whether or not to use or adapt the information or content provided in each circumstance. Notwithstanding the medical or physical condition of each user, no responsibility or liability is accepted and all responsibility and liability is hereby disclaimed for any loss or damage suffered by any person as a result of the use or misuse of any of the information or content in this website, and any and all liability for incidental and consequential damages is hereby expressly excluded.
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Nov 25, 2011 @ 6:18 pm
I am studying biological engineering at USU and would like any information anyone can give me on the purification of insulin in industry. The production of insulin is interesting to me and I am doing a paper on how it is purified. Thanks in advance for the information
michelle
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Apr 11, 2012 @ 5:05 am
I am trying to understand how alcohol affects the pancreas anyone shed some light please
alfred
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May 22, 2013 @ 12:12 pm
if the beta cells produce insufficient insulin, how can the body compensate for this prior to given insulin cultured from E. coli

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