GLUCOSE TRANSPORTERS AND DIABETES

Peripheral insulin resistance is a characteristic feature of obesity a nd non-insulin-dependent diabetes mellitus (NIDDM), and the cause can be localized in part to a defect in glucose transport. GLUT4, the pred ominant glucose transporter in insulin sensitive tissues, undergoes st riking tissue specific metabolic regulation; GLUT4 gene expression is reduced in adipocytes, and generally unchanged in muscle from insulin resistant humans and rodents. rn adipocytes, lower levels of GLUT4 acc ount for the glucose transport defect, whereas in muscle, impaired tra ffic or decreased function of GLUT4 at the plasma membrane may account for the defect. Future studies of GLUT4 translocation, fusion and exp osure/activation will unravel the molecular mechanism(s) behind the de velopment of insulin resistance. (C) 1996 Academic Press Ltd