1. Dr. Rajendran. Swww.medicinemcq.com1

2. Blood glucose regulates insulin secretion Insulin regulates blood glucosewww.medicinemcq.com 2 3. Direct feedback effect on pancreatic beta cells When plasma glucose When plasma glucose Insulin secretion Insulin secretion Great precisionwww.medicinemcq.com 3 4. PancreasBlood glucoseInsulinwww.medicinemcq.com 4 5. Insulin regulates blood glucose Glucose production by the liver Uptake and utilization in peripheral tissues Muscle Adipose tissue Liverwww.medicinemcq.com 5 6. 80 to 90 mg/100 ml Rate of insulin secretion is lowPlasma glucose < 75 mg / dl Insulin secretion inhibitedwww.medicinemcq.com 6 7. > 75 mg/dL Stimulate insulin synthesis and insulin secretionBlood glucose > 100 mg/100 ml Insulin secretion rises rapidlywww.medicinemcq.com 7 8. Glucose between 300 and 500 mg / dlwww.medicinemcq.com 8 9. Glucose enters B cells via GLUT 2 Pancreas Beta cell glucose sensor Insulin independentwww.medicinemcq.com 9 10. www.medicinemcq.com10 11. www.medicinemcq.com11 12. www.medicinemcq.com12 13. www.medicinemcq.com13 14. Controls glucose-regulated insulin secretion Phosphorylation Rate-limiting step in glucose metabolism in the beta cell and insulin releasewww.medicinemcq.com 14 15. Incretins GI hormones that potentiate insulin secretion Cause 50% of the insulin released after a mealwww.medicinemcq.com 15 16. Glucagon Like Peptide-1 (GLP-1) Gastric Inhibitory Peptide (GIP)www.medicinemcq.com 16 17. Released from small-intestinal endocrine cells postprandially Reach the beta cells through the bloodstream Increase the sensitivity of islet cells to glucosewww.medicinemcq.com 17 18. Insulin secretion greater after oral than after intravenous glucose administrationwww.medicinemcq.com 18 19. GlucoseIncretinsInsulinwww.medicinemcq.com 19 20. www.medicinemcq.com20 21. www.medicinemcq.com21 22. www.medicinemcq.com22 23. Stimulates insulin secretion Increases beta cell mass Inhibits glucagon secretion Delays gastric emptyingwww.medicinemcq.com 23 24. Raises levels of cAMP Activates cAMP-dependent protein kinase A Amplify the Ca2+ signal by decreasing Ca2+ uptake by cellular storeswww.medicinemcq.com 24 25. Stimulates insulin secretion when glucose levels are elevated Decreases glucagon-stimulated hepatic glucose productionwww.medicinemcq.com 25 26. Amplify the glucose-induced release of insulin from the beta-cell Stimulate insulin release in the absence of glucose Most potent Arginine Lysine Leucine www.medicinemcq.com 26 27. Amino acid metabolism and ATP generation Elevated beta-cell Ca2+ concentrationswww.medicinemcq.com 27 28. Only minor effects on insulin releasewww.medicinemcq.com 28 29. Promote the secretion of insulinwww.medicinemcq.com 29 30. Beta2 Enhance insulin secretionAlpha2 Inhibits insulin releasewww.medicinemcq.com 30 31. Suppresses the secretion of insulin Stimulation of alpha2 adrenergic receptors andinhibition of insulin secretion Hypoxia Hypoglycemia Exercise Hypothermia Surgery Severe burns www.medicinemcq.com 31 32. Alpha 2 Increase basal concentrations of insulinBeta2 Decrease basal concentrations of insulinwww.medicinemcq.com 32 33. Inhibit insulin secretionwww.medicinemcq.com 33 34. Inhibit insulin secretion Through G proteincoupled receptor (GPCR)mechanisms Inhibit adenylate cyclase Modify Ca2+ and K+ channel gating.www.medicinemcq.com 34 35. Stimulates insulin secretion Insulin inhibits glucagon secretionwww.medicinemcq.com 35