Effects of high cholesterol and n-3 polyunsaturated fish oil diets on tissue and serum lipid composition in male rats.

The correlation between dietary cholesterol, high plasma lipids and cardiovascular disease is well recognized in many species. The purpose of the present study was to examine the effects of high cholesterol and moderately high fat intake of n-3 polyunsaturated fish oil diets on serum lipids in male rats. Male rats were fed either 21% menhaden oil (Control) or 21% menhaden oil with high (2%) cholesterol (MOC) for eight weeks. Whole blood was collected, and analyzed spectrophotometrically for serum cholesterol, triglycerides and lipoproteins. The selected tissues were carefully removed, weighed and analyzed for lipid profiles. The aortas were removed and lipogenesis determined. The results showed that except for spleen the total percent lipid content of heart, lung, liver, adrenal, kidney and brain was not affected in the MOC group. The percent fat content of spleen but not the weight was elevated by 4 fold compared to control. The hematocrit values in the MOC group were unaltered. Serum cholesterol was elevated by 62%, whereas the serum triglycerides and HDL cholesterol were unaltered in MOC group when compared to the MO control. High cholesterol feeding did not affect aortic lipogenesis in the MOC group compared to the control. These results suggest that cholesterol feeding along with n-3 polyunsaturated fish oil diet did not attenuate the anti-atherosclerotic effects of fish oil with the exception of serum cholesterol.