Expression of insulin regulatable glucose transporters in skeletal muscle from type 2 (non-insulin-dependent) diabetic patients

A prominent feature of Type 2 (non-insulin-dependent) diabetes mellitus is the inability of insulin to appropriately increase the transport of glucose into target tissue. In adipocytes from individuals with Type 2 diabetes, insulin resistance has been shown to be associated with a depletion of glucose transporters. Similarly, streptozotocin induced diabetes causes a diminished expression of the insulin regulatable glucose transporter in rat adipocytes. The expression of this glucose transporter isoform has not yet been investigated in muscle tissue from patients with Type 2 diabetes. We have measured the content of the insulin regulatable glucose transporter in a vesicular fraction isolated from muscle biopsies from fasting individuals with Type 2 diabetes and control subjects, and we found that the number of the insulin regulatable glucose transporters expressed in skeletal muscle was unaffected by Type 2 diabetes (0.208 vs 0.205, arbitrary units, p greater than 0.5, control subjects and diabetic patients). Thus, the decreased glucose disposal in Type 2 diabetes is not associated with a diminished number of insulin regulatable glucose transporters.