Lipids as endogenous Na, K-ATPase inhibitors in plasma of healthy individuals and in dialysis dependent patients

We assayed plasma Na,K-ATPase inhibitory activity due to total lipids and lipid fractions. The effect of dialysis on the Na,K-ATPase inhibitory activity was also studied. Plasma lipid extracts from 11 healthy volunteers and 9 dialysis-dependent patients (pre and post dialysis) were separated into neutral lipids and phospholipids. Further fractionation was by thin layer chromatography. These lipids fractions were analyzed for Na,K-ATPase inhibitory activity by displacement of [ 3 H]-ouabain from hog brain Na,K-ATPase. Total inhibitory activity was significantly increased ( p in vitro under these assay conditions.