The effects of captopril and losartan on erythrocyte membrane Na+/K(+)-ATPase activity in experimental diabetes mellitus.

Diabetes mellitus induces a decrease in sodium potassium-adenosine triphosphatase (Na+/K(+)-ATPase) activity in several tissues in the rat and red blood cells (RBC) and nervous tissue in human patients. This decrease in Na+/K(+)-ATPase activity is thought to play a role in the development of long-term complications of the disease. Angiotensin enzyme inhibitors (ACEi) and angiotensin-II receptor antagonists (ARBs) reduce proteinuria and retard the progression of renal failure in patients with IDDM and diabetic rats. We investigated the effects of captopril and losartan, which are used in the treatment of diabetic nephropathy, on Na+/K(+)-ATPase activity. Captopril had an inhibitory effect on red cell plasma membrane Na+/K+ ATPase activity, but losartan did not. Our study draws attention to the inhibitory effect of captopril on Na+/K+ ATPase activity. Micro and macro vascular complications are preceeding mortality and morbidity causes in diabetes mellitus. There is a strong relationship between the decrease in Na+/K+ ATPase activity and hypertension. The non-sulphydryl containing ACEi and ARBs must be the choice of treatment in hypertensive diabetic patients and diabetic nephropathy.