Effect of polyphenolic compounds on the renal Na+, K+-ATPase during the restoration of normotension after experimentally induced hypertension in rats

Abstract

It is commonly known that consumption of foods and beverages rich in polyphenols is associated with a lower incidence of cardiovascular disease. The purpose of this study was to assess whether the application of red wine polyphenols influences the kinetic properties of renal Na+,K+-ATPase in rats in which hypertension has been experimentally induced by the nitric oxide synthase inhibitor L-NAME. Treatment with polyphenols during the recovery from hypertension to normotension resulted in the complete revival of the functional properties of the Na+,K+-ATPase, as indicated by the total restoration of Km, KNa (concentration ofNa+ necessary to achieve half-maximal reaction velocity) and Vmax for enzyme activation by ATP and/or Na+ to pre-hypertension values. Two positive effects of polyphenols during the recovery period are indicated: a restoration of the affinity of the ATP and Na+ binding sites to control values and a probable increase in the number of Na+,K+-ATPase molecules to a level comparable to that in control conditions, as suggested by the complete renewal of Vmax.