2型糖尿病诊治 课件.pptVIP

DISCUSSION By decreasing beta-cell workload and improving beta-cell response, the incretin glucagon-like peptide 1 (GLP-1) is an important regulator of glucose homeostasis A thorough understanding of the 5 GLP-1 glucoregulatory effects is important to assess the value of GLP-1 in controlling glucose levels, particularly during the postprandial period Upon ingestion of food, GLP-1 is secreted in into the bloodstream and enhances glucose dependent insulin secretion from beta-cells GLP-1 suppresses inappropriately elevated glucagon secretion from alpha cells Lower levels of glucagon lead to a reduction of glucose output from the liver and indirectly reduce the beta-cell workload By slowing the gastric emptying rate, GLP-1 slows the release of nutrients into the gut allowing more time to control the postprandial increase in glucose levels GLP-1 promotes satiety, potentially through centrally mediated mechanisms BACKGROUND GLP-1 is secreted from L cells of the small intestine GLP-1 decreases beta-cell workload, hence the demand for insulin secretion, by: Regulating the rate of gastric emptying such that meal nutrients are delivered to the small intestine and, in turn, absorbed into the circulation more smoothly, reducing peak nutrient absorption and insulin demand (beta-cell workload) Decreasing postprandial glucagon secretion from pancreatic alpha cells, which helps to maintain the counterregulatory balance between insulin and glucagon Reducing postprandial glucagon secretion, GLP-1 has an indirect benefit on beta-cell workload, since decreased glucagon secretion will produce decreased postprandial hepatic glucose output Having effects on the central nervous system, resulting in increased satiety (sensation of satisfaction with food intake) and a reduction of food intake Effect on Beta cell: Drucker DJ. Diabetes. 1998;47:159-169. Effect on Alpha cell: Larsson H, et al. Acta Physiol Scand. 1997;160:413-422. Effects on Liver: Larsson H, et al. Acta Physiol S