Beta Cells

General
1

Hi All,

I've always thought that the cells that make insulin are called the islet of langerhans or beta cells.

But just discovered that really beta cells are just a subset of cells in the islet of langerhans and there are alpha cells, delta cells, pp cells.

Now, my understanding is that it is only our beta cells that don't work and the other cells are ok.  Is that right???

That is now how I am understanding it- it is really only our beta cells- because after having T1 diabetes for 27 years, I am just realizing that it is not only insulin we don't have, but the other hormone amylin!!  I kind of feel ripped off that my endocronologist never told me that or I really never read that until the last year with the release of symlin and all the talk about that.

I just want to understand it better and know for sure that it is only insulin and amylin that my body doesn't make.

I know this is a dr. question, but am not going to my doctor anytime soon and really want to understand this better now.

Can anyone enlighten me??

Laura

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2

to put it simply: you're correct (as far as i understand it as well)! our pancreas does a lot more than just produce insulin. just because our pancreas doesn't produce insulin, doesn't mean our entire pancreas is "broke"... just the insulin making part :o) our pancreas also plays a huge role in the creation of hormones and digestive enzymes. insulin is just one tiny part of our endocrine system. we're lucky everything else still works!

3

From what I understand, it's more recently that researchers learned about amylin, compared with how long they've known about insulin. Also, until symlin, there wasn't much they could do about it and it's not fatal. So, that's probably why no one mentioned it.

But, it does make me worry what else we're missing that we don't know about, huh! (Perhaps my sanity is in there somewhere?)

4

Yes you are correct. There are multiple different cell types in the Islets of Langerhans, beta cells being one type. Beta and alpha cells also work together. Beta cells produce insulin, which "shuts off" alpha cells. Alpha cells produce glucagon, which in turn "shuts off" beta cells. Other things control these "on/off" switches as well, but in a basic sense, this is what they do. Both are linked to glucose absorption into the body. Insulin triggers the body to remove glucose from the blood stream, give it to cells for energy, and to store any left-over as fat. Glucagon is normally triggered by low blood sugar or cells needing glucose, causing the body to break down fat to release glucose back into the bloodstream. This is why you get a "glucagon emergency kit" for treating insulin OD. Injecting a large quantity will over ride the access insulin in your system and stop your body from sucking all the glucose out of your blood and will release some from "storage" aka fat.

This whole system is much more complex than this, and is very tightly controlled/regulated, but as a brief overview, this is what goes on. Since our beta cells "bit the dust", our control system sucks and the "on/off" switches don't work the same.

5

Thanks Megan!  I really didn't know that the alpha cells work in conjunction with the beta cells like that.  I read that the alpha cells produce glucagon, but you explained it well

So, let me get this straight- beta cells don't work at all, alpha cells kind of really don't work properly because of the fact that our beta cells don't work and it affects them-

So one more question and please give me some input if you know......

Do the other cell types (besides beta and alpha) work perfectly fine?

I just want to know and not be surprised again like finding out we also don't produce amylin!!!

6

Soo Funny that you posted this.  Cuz just today I was reading about amlyn... and was like WHAT? totally felt ripped off. Now I am on a mission to find out more. lol. 

7

Soo Funny that you posted this.  Cuz just today I was reading about amlyn... and was like WHAT? totally felt ripped off. Now I am on a mission to find out more.

8

As far as I know, the other cells work just fine. Your immune system specifically attacked beta cells, the others should be ok, unless there is some other kind of underlying condition, none that I know, but I am certainly no expert. Or it hasn't been discovered/validated yet. It takes a while for new science to actually make it to the public sector and have an impact.

9

[quote user="Megan519"]

... will release some from "storage" aka fat.

[/quote]

Actually the first storage glucagon releases is liver glycogen, not fat. When you eat and take insulin, your body restores blood glucose first, then switches to liver and muscle glycogen, then switches to storing as fat. Glucagon inhibits the action of insulin and prompts the liver to convert its glycogen stores to glucose, which is then released into the blood stream where it can be taken up by the brain and (assuming the presence of insulin or exercise) muscles. Glucagon will break down fat and release free fatty acids (and ketones) only once the liver glycogen stores are depleted. 

 

Like you said, the beta cells dysfunction makes the alpha cells somewhat dysfunctional - though they are not technically broken; the system is just broken by the beta cells. The same is true of delta cells, and PP cells, and also some other endocrine cells, like the adrenal glands. Delta cells produce GHIH (growth hormone inhibiting hormone) which (surprise) inhibits the action of growth hormone. The most obvious effect of growth hormone is the increased insulin resistance in the morning known as dawn phenomenon - again, happens in people without diabetes as well, but it doesn't cause problems because the larger system isn't being strained by dysfunctional beta cells. Epinephrine (or adrenaline) is a similar story. Cortisol also has effects on blood sugar. Endocrine function is enormously convoluted, and everything is secondarily or tertiarily affected by the dysfunction of beta cells. 

 

However, as far as I know the majority of people with T1 have absolute deficiencies of insulin and amylin and nothing else. However, there are still not that many studies done on T1 folks, and science is constantly evolving, so we may find out next week that type 1 also causes a definciency of something else. And this ignores the increased likelihood for other autoimmune endocrine disorders i.e. hashimotos. 

 

Between the time scientists isolated amylin and scientists were able to create injectable amylin, most health care providers who worked with T1 people thought that, when amylin became available, everyone would be on it. Then it came out, and they found that it had almost no effect on control over a large population and caused a lot of stress because it meant three more injections every day, caused people to feel nauseated, relied on people to adequately assess their carb intake before eating in a new way, etc. That isn't to say that it's not good for some people - it can really help some people with constant hunger (and i think other things, also, but i don't know much more about it.).

 

I am kinda a layman's endocrinology geek. I did this for a class last semester. I think it's fascinating. 

10

Haha you caught me. I skipped the glycogen because I thought it was a little "deep" for the general audience and I didn't want to confuse people too much. High five for knowing your stuff!

11

I think the others still work fine. Because otherwise how could the pancreas perform its job as a key digestive organ? It secretes some pretty important stuff to aid with digestion.