The Pancreas and Pancreatic Hormones

The pancreas is an exocrine and an endocrine organ. The acinar cells secrete proteolytic, lipolytic and amylytic enzymes in the pancreatic juice that flows through a ductal network to the duodenum. These enzymes are important for digestion. The pancreatic islets of Langerhans in the pancreas secrete hormones into the blood that are essential for maintenance of normal blood glucose levels or euglycemia. Diabetes mellitus is a disease of the endocrine pancreas. Type 1 diabetes is characterized as an absolute lack of insulin in the B-cells of the pancreatic islet. Insulin must be replaced for optimal control of blood glucose levels. Type 2 diabetes is characterized by a relative insufficiency of insulin secretion and peripheral insulin resistance. Oral hypoglycemic agents, injectable incretins and insulin are used to control blood glucose levels in type 2 diabetes. Oral hypoglycemic agents can target insulin secretion, hepatic glucose release, kidney glucose transporters, and glucose uptake and metabolism in insulin target tissues. Carbohydrate metabolism in the GI tract is also a target for reducing prandial glucose levels in blood. Maintaining euglycemia often requires combination pharmacologic therapy.