Can protein kinase C inhibition and vitamin E prevent the development of diabetic vascular complications?

Hyperglycemia causes vascular complications of diabetes possible by the act ivation of protein kinase C (PKC). We have provided substantial evidence th at activation of PKC can lead to a whole host of vascular dysfunction in di abetes. The activation of PKC induced by hyperglycemia appears to be due to an increase in diacylglycerol (DAG) levels, a physiological activator of P KC. Studies involving cultural cells, animal models of diabetes and patient s have shown that inhibition of PKC by specific PKC-up down arrow inhibitor was able to reverse many of the vascular dysfucntions in the retina, kidne y and cardiovascular systems induced by either hyoperglycemia or diabetes. In addition high doses of vitamin E were shown to decrease the level of DAG and PKC induced by diabetes or hyperglycemia. Thus animal and clinical stu dies have shown that high doses of vitamin E treatment can apparently rever se some of the changes in the retinal and renal vessels. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.