The rate of transbilayer movement of erythrocyte membrane cholesterol is correlated with sodium-lithium countertransport.

Abstract

Hypertension is associated with some abnormalities in cell membrane structure, including an impaired distribution of cholesterol into the monolayers of erythrocyte membrane. Transbilayer movement of membrane cholesterol modulates the formation of these structural cholesterol domains. We tested whether the rate of cholesterol movement may influence on the erythrocyte Na(+)-Li+ countertransport, that is a marker of human essential hypertension. In single regression analysis, the half-time for the decrease in specific radioactivity of cholestenone (inverse of membrane cholesterol transbilayer movement) was negatively related to the erythrocyte cation flux mediated by Na(+)-Li+ countertransport (r = -0.8983, P < 0.0001 for control subjects; r = -0.8191, P < 0.005 for normocholesterolaemic hypertensive patients; r = -0.7664, P < 0.005 for hypercholesterolaemic hypertensive patients). These data suggest that changes in the transbilayer movement of membrane cholesterol interfere with the main cation transport system which is implicated in the pathophysiology of essential hypertension. This also provides a new link between kinetic cholesterol pools and cell membrane functions.