An investigational diabetes treatment involving a hypoglycemia-inducing drug has been developed. This drug is designed to inhibit dipeptidylpeptidase IV (DPP4) activity and has been shown to decrease plasma glucose concentration and pancreatic glucagon secretion. DPP4 hydrolyzes which of the following hormones such that its inhibition results in the observed effects?

Question

Quizplus · Accepted Answer

DPP4 hydrolyzes glucagon-like peptide-1 (GLP-1), which stimulates insulin secretion and inhibits glucagon secretion. Inhibition of DPP4 results in increased GLP-1 levels, which leads to decreased plasma glucose concentration and pancreatic glucagon secretion.  GLP-1 stimulates postprandial insulin secretion and has also been shown to stimulate proliferation and inhibit apoptosis of pancreatic β-cells. GLP-1 also inhibits glucagon release from pancreatic α-cells, inhibits gastric emptying, and reduces food intake. DPP4 is involved in the degradation of GLP-1, thus DPP4 inhibitors act to prevent inactivation of and prolong the duration of action of GLP-1.

An Investigational Diabetes Treatment Involving a Hypoglycemia-Inducing Drug Has Been