Hyperglycemia, polyol metabolism, and complications of diabetes mellitus.

This brief review of the sorbitol pathway has attempted to present our current knowledge of this accessory pathway of glucose metabolism in the development of some diabetic complications. Clearly hyperglycemia in the diabetic patient is an important factor controlling the activity of the sorbitol pathway. Hyperglycemia in both diabetic patients and experimental animals results in significant accumulations of the products of this pathway in some tissues, and these diabetic manifestations. The development of inhibitors of the aldose reductase enzyme affords new means for preventing and treating some of these complications. Nevertheless, we are still hampered by the lack of knowledge of the normal role of this pathway in tissue metabolism. Many technical problems still exist concerning sensitive and specific assays for the products of the sorbitol pathway in tissue studies, as well as with valid techniques for the measuremtn of the activity of this pathway in clinical situations. It is hoped that clinical studies with aldose reductase inhibitors in the future will further clarify the importance of this accesory pathway of glucose metabolism in diabetes.