Influence of Experimental Hypertension on Cholesterol Esterification and Hydrolysis of Cholesterol Esters in Rat Aortae, Liver and Serum

Abstract

In rats with experimental hypertension the esterification of cholesterol and hydrolysis of cholesterol esters in aortae, blood serum and liver was investigated in vitro at atmospheric pressure and at raised pressure of 200 Torr, i.e. a pressure similar to that recorded in the arteries of hypertensive animals in vivo. Hydrolysis of cholesterol esters was enhanced in hypertensive animals. The increase could be detected on incubation in vivo at atmospheric pressure and at 200 Torr in serum and aortae, but in the liver only at atmospheric pressure. In hypertensive rats no decline of hydrolysis in serum and aortae, which was associated with incubation at 200 Torr in normotensive rats, was observed. Cholesterol esterification in serum in vitro was greater at 200 Torr, while in aortae it declined. In hypertensive rats esterification in serum was reduced, in aortae enhanced and in the liver the changes were not significant. The results are discussed with regard to atherogenesis in hypertension and with regard to enzyme adaptability.