Insulin receptor and insulin resistance in type -2 diabetes

Abstract

Resistance to the glucoregulatory effects of insulin is well-documented in type -2, non-insulindependent diabetes. Two separate factors may contribute in the pathogenesis, namely the obesity-related and the non-obesity-related.
Obesity-related insulin resistance is associated with hyperinsulinemia, reduced numbers of insulin receptors on target cells. The mechanism by which the insulin receptor number is decreaSed is not clearly understood. This phenomenon is called "down regulation". If the defect in glucose transport can not be overcome at any insulin concentration, insulin unresponsiveness is present. This is caused by unidentified abnormalities distal to the receptor, "postreceptor defect".
In non-obesity-related, a-cell dysfunction, secretion of abnormal insulin, failure to convert proinsulin to insulin, or hormonal antagonist to insulin, is thought to be responsible for the resistance.

Key Words: type -2 diabetes mellitus - insulin receptor - insulin resistance - insulin antagonist - obesity-related and non-obesity-related factors