Islets of Langerhans

Islets of Langerhans is a special group of cells in the pancreas. There are four types of cells in the Islets of Langerhans. ‘A’ cells secrete a hormone called glucagons, ‘B’ cells secrete insulin, ‘D’ cells secrete somatostanin and the ‘F’ cells secrete pancreatic polypeptide. Of these hormones, glucagons, insulin and somatostanin, plan an important role in balancing blood- sugar level. Excess or deficiency of any of these three hormones causes diabetes mellitus and other blood-sugar level complications. Insulin deficiency, either absolute or relative, causes diabetes mellitus, which is a complex disease and if untreated, is eventually fatal. Insulin in excess causes hypoglycemia. Hypoglycemia is a condition, in which the blood-sugar level is present below the normal level i.e. below 80 mg per 100 ml blood. Hypoglycemia may lead to the person developing convulsions and coma.

However, hypoglycemic symptoms are relieved by the administration of glucose. But occassional hypoglycaemic episodes are the price of good diabetic control.

The reverse is the effect of the hormone glucagons. Somatostanin, if secreted in excess leads to hyperglycemia and other manifestations of diabetes.