Relationship of Na-K-ATPase inhibitors to blood-pressure regulation in continuous ambulatory peritoneal dialysis and hemodialysis

Abstract

Inhibitors of sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) have been implicated in the pathogenesis of hypertension. In the study presented here, an attempt was made to determine whether differences in the plasma levels and the removal rates of high-molecular weight (HMW) and low-molecular weight (LMW) forms of Na-K-ATPase inhibitors might relate to blood-pressure control in hemodialysis (N = six ultrafiltered and N = six nonultrafiltered) and CAPD (N = six long-term and N = five short-term) patients. The latter group was studied before the initiation of continuous ambulatory peritoneal dialysis (CAPD) and 2 wk after starting the treatment. The mean blood pressure was significantly reduced after dialysis in the nonultrafiltered hemodialysis group and in both CAPD groups. Plasma levels of both HMW and LMW inhibitors were found to be elevated before dialysis in all patients and were modified only slightly after dialysis, irrespective of whether ultrafiltration was utilized in hemodialysis patients and despite significant losses of both HMW and LMW inhibitors into CAPD effluent. Because CAPD effluent was found to contain vasopressors that were not exclusively Na-K-ATPase inhibitors, losses of these other vasopressors may contribute to improved blood-pressure control in CAPD in contrast to hemodialysis.