Hypertension does not stimulate the development of hypercholesterolemia or fatty liver induced by a high cholesterol/cholate diet in rats.

A high cholesterol/cholate diet induced hypercholesterolemia and fatty liver in both spontaneously hypertensive rats (SHR) and normotensive control rats (WKY). However, in contrast to previous concepts, the levels of cholesterol ester, triacylglycerol and phosphatidylcholine in plasma as well as triacylglycerol in liver were higher in WKY than in SHR fed a normal diet. The high cholesterol/cholate diet elevated the levels of plasma cholesterol, plasma cholesterol ester and hepatic triacylglycerol, and the extent of elevation was significantly higher in WKY than in SHR. Increases both in monoene/saturated ratios, an indication of elevated delta 9-desaturase activity, and in linoleate/arachidonate ratios, a possible indication of impaired desaturation-elongation activity, were observed in hepatic and plasma lipids of both strains fed the high cholesterol/cholate diet. The increases in monoene/saturated ratios were similar in both strains, but the increases in the linoleate/arachidonate ratios were higher for the plasma cholesterol esters of WKY than of SHR. The n-6/n-3 ratios of plasma and hepatic lipids were higher in WKY than in SHR throughout the experiments. These diet-induced changes observed in hepatic and plasma lipids were not reflected in the aortic lipids. Thus, hypertension per se does not promote the development of hyperlipemia and fatty liver induced by a high cholesterol/cholate diet. Our results also suggest that the metabolism of polyenoic fatty acids is different between SHR and WKY.