Insulin receptors: their roles in the pathogenesis and management of type II diabetes mellitus.

In Type II Diabetes Mellitus associated with insulin resistance, the defect is in insulin action. This may take the form of decreased insulin sensitivity, responsiveness, or both. The decrease in insulin binding is due to a decrease in the number of insulin receptors per cell. When the obese Type II diabetic loses weight after being on a weight reducing diet, the insulin sensitivity abnormality is restored towards normal. In so doing the number of insulin receptors per adipocyte or monocyte is restored towards normal. The effect of exercise on insulin binding in skeletal muscles of Type II diabetics has not been studied. Recent experiments in rodents and humans indicate that insulin binding is not affected by acute exercise but the post-receptor events are increased. Finally oral hypoglycemic medications can increase the insulin sensitivity and/or the insulin responsiveness of various tissues.