Dietary and gonadal hormone effects on lipid metabolism in the rat

[摘要] Hepatic cholesterol, triglyceride, and phospholipid concentrations, plasma cholesterol levels, cholesterol biosynthesis, and fatty acid patterns in plasma lipids and liver lipid fractions, have been studied in intact, gonadectomized, and hormone-treated gonadectomized male and female rats fed a fat-free diet, a control diet containing fat, and a diet containing cholesterol, to determine relationships between diet, sex hormones, and lipid metabolism.Both estradiol benzoate and testosterone propionate affected lipid metabolism; in general, the estrogenic influence was more pronounced and more predictable. The greatest effects were found in animals fed the essential fatty acid-deficient diet (a sex difference in susceptibility to essential fatty acid deficiency has previously been reported). It is concluded that the effect of estrogenic deficiency on lipid metabolism includes: (a) decreased hepatic cholesterol biosynthesis; (b) increased hepatic sterol ester and decreased phospholipid concentration; (c) increased depletion of unsaturated fatty acid in plasma and liver during essential fatty acid deficiency; and (d) increase in severity of essential fatty acid deficiency symptoms, using as criteria the ratios of trienoic to tetraenoic fatty acids in plasma and liver lipids.

[关键词] gonadectomy;sex hormones;diet;lipid metabolism;rat;liver