Incretin hormones (GLP-1 and GIP) released from the intestine in response to meal ingestion
augment insulin secretion from the pancreas to help maintain glycemic control. Studies in
vitro and in vivo have shown that these incretin hormones also have functional effects in
other tissues independent of the insulin secretory response. Both GLP-1 and GIP stimulate
insulin secretion in a glucose-dependent manner, however the glucose-dependency of their
extra-pancreatic effects has not been examined in vivo. By using pancreatic clamp methodology
during euglycemic and hyperglycemic conditions we will test the hypothesis that
extra-pancreatic effects of GLP-1 and GIP are glucose-dependent.