Adenylate cyclase activity and cAMP content of human platelets in uraemia.

Abstract

We investigated the effects of uraemia and haemodialysis on the basal activity of adenylate cyclase and the cyclic-AMP content of human platelets in patients with end-stage renal insufficiency, patients receiving maintenance haemodialysis, and as controls healthy voluntary subjects. Basal adenylate cyclase activity in terminal renal disease (creatinine clearance less than 15 ml/min/1.73 m2) was 824 +/- SEM 57, in comparison to the healthy subjects with 453 +/-SEM 28 (P less than 0.001). We also found significant elevation (P less than 0 . 001) of platelet cAMP levels as compared to the controls. Basal adenylate cyclase activity and platelet cAMP levels were approximately normal in the dialysed patients. These results show that uraemic toxins adversely affect the platelet AC-cAMP system, possibly causing impaired platelet aggregation and the bleeding diathesis of uraemia.