Serum cholesterol levels and the ratio of polyunsaturated to saturated fatty acid as an indicator of lipid metabolism in rat liver.

Abstract

SummaryTne dietary effects of phytosterol and polyunsaturated fat (PUFA-fat) on the cholesterol and fatty acids levels in serum and liver of female rats were studied, with the following results.(1) Addition of 1 cholesterol with 0.25% cholic acid to a 10% butter diet increased cholesterol levels and decreased the ratio of polyunsaturated fatty acid (PUFA) to saturated fatty acid (SFA) in the serum and liver. These changes diminished upon additions of phytosterol and PUFA-fat (cod liver oil) to the 10% butter-cholesterol diet. (2) While the cholesterol-rich diet increased the fatty acid content of the liver, addition of phytosterol to the butter-cholesterol diet depressed this increase. On the other hand , addition of PUFA-fat to the butter-cholesterol diet caused an increase of total fatty acid in the liver. (3) A negative relationship was found between the cholesterol level and the ratio of PUFA to SFA in serum (r=-0 .810) and also in liver (r=-0.548). There were significant positive correlations between the values for the serum and liver cholesterol levels (r=0 .720) and also between the respective values in the ratios of PUFA to SFA (r=0.521). These results indicate that dietary phytosterol and PUFA-fat modulate the levels of cholesterol in proportion to the increase in the ratio of PUFA to SFA in both serum and liver with the cholesterol diet , and show that the changes in the values for the serum reflected in changes in the liver.

Effects of Dietary Cholesterol Level on Heart Cholesterol and Palmitoleic Acid in Female Rats

“…The change in serum cholesterol was correlated with that in the liver (r=0.67). This correlation agreed with previous results using dietary fats and phytoster of in 1 % cholesterol diets [9]. Therefore, these correlations seem to reflect the effects of dietary factors such as cholesterol, fats, and phytosterol on cholesterol metabolism.…”

“…Saponification of serum and homogenized liver and heart and preparation of sterol and fatty aid fractions were carried out according to standard methods of the Japan Oil Chemists' Society for analysis of fats and oils [11]. Cholesterol and fatty acids were analyzed by gas liquid chromatography as reported previously [9] with some modification. The sterol fraction was loaded onto a 1-m glass column packed with 3% Ov-1 coated on 100-120 mesh Gaschrom ~Q (Gasukuro Kogyo) at a column temperature of 250°C with nitrogen as the carrier gas (40 ml/min).…”

“…ously changes in fatty acid composition and cholesterol level in serum and liver caused by dietary cholesterol and fats [8,9]. However, the effects of dietary cholesterol on cholesterol and fatty acid metabolism in the heart are not clear.…”