9. Incretins

Question 1

what is the effect of GLP1 on the brain

Answer 1

Promotes satiety and reduces apetite

Question 2

what is the effect of GLP1 on alpha cells

Answer 2

suppresses postprandial glucagon secretion

Question 3

what is the effect of GLP1 on the liver

Answer 3

reduces hepatic glucose output

Question 4

what is the effect of GLP1 on the stomach

Answer 4

slows rate of emptying

Question 5

what is the effect of GLP1 on beta cells

Answer 5

enhances glucose dependent insulin secretion in the pancreas

Question 6

How do sulphonylureas work?

Answer 6

bind SUR1 receptor, causing the K+ channel to be closed, which depolarises the cell leading to Ca++ influx and exocytosis of insulin.

Question 7

How do thiazolidinediones work?

Answer 7

bind PPARgamma nuclear receptor which is coupled to RXR. Enhanced transcription of : GLUT4, fatty acid transported protein, fatty acyl CoA synthase.
Leads to increased glucose uptake and increased lipogenesis and decreased circulating fatty acids.

Question 8

what is thought to be the mode of action of metformins?

Answer 8

1. reduction of hepatic gluconeogenesis
2. decreased absorption of glucose from the GI tract
3. decreased insulin sensitivity - increased peripheral glucose uptake

Question 9

How do alpha glucosidase inhibitors work?

Answer 9

competitive inhibitors of the enzymes needed to break down carbohydrates

Question 10

What are the short term and long term effects of alpha glucosidase inhibitors?

Answer 10

short term: decrease blood glucose

long term: reduction in HBA1c levels

Question 11

3 examples of alpha glucosidase inhibitors?

Answer 11

1. acarbose - oligosaccharide - not well absorbed
2. miglitol - monosaccharide - well absorbed
3. volglibose - less side effects