Insulin Secretion and Regulation

by Thad Wilson, PhD

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    Regulation of Insulin secretion. So what regulates insulin secretion. Meals are one of the biggest stimulatory events. A meal is thought up to be very important because you are going to start getting blood glucose after a meal. Therefore, you want insulin levels high to dry that glucose into cells. So having high insulin levels after a meal makes a lot of sense. There are few agonist that we'll go through one at a time. Such as neural ones. Other ones from the GI system as well as from the pancreas. There are few antagonist that we'll deal with first. And that has to do with norepinephrine. And norepinephrine is usually released during the sympathetic stimulatory event. As well as somatostatin. If you remember back that glucagon, you could see somatostatin not only inhibits insulin secretion but also glucagon secretion. Now let's look through the meal in a little bit more detail. What about a meal stimulates insulin to be secreted? Glucose probably is the biggest stimulant. Although amino acids and free fatty acids can also be part of the process. Let's talk through glucose. Glucose enters a beta cell by a glute II receptor. Following the concentration gradient. It then undergoes metabolism and ATP is produced. That ATP that's produced is going to bind to a potassium channel sensitive to ATP. That closes that channel. And as that channel closes potassium is no longer allowed to leave the membrane. If potassium which is a positively charged ion, is not allowed to leave, positive charges start building up within the cytosol in this beta cell. What does that do? It starts to depolarize the cell. As that cell depolarizes, it's eventually going to reach a threshold for calcium. This L-type calcium channel will open allowing calcium influx into the cytosol...

    About the Lecture

    The lecture Insulin Secretion and Regulation by Thad Wilson, PhD is from the course Endocrine Physiology.

    Included Quiz Questions

    1. Acetylcholine
    2. Glucose
    3. Pancreatic polypeptide
    4. Cholecystokinin

    Author of lecture Insulin Secretion and Regulation

     Thad Wilson, PhD

    Thad Wilson, PhD

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