REEVALUATION OF THE REGULATORY FUNCTION OF SATURATED FATS ON CHOLESTEROL METABOLISM;STUDIES WITH INTERESTERIFIED FATS.

研究了饲粮中添加月桂酸、肉豆蔻酸、棕榈酸和硬脂酸对脂质代谢的影响。当给大鼠喂食补充胆固醇的食物时，这些饱和脂肪酸不影响血清脂质的浓度。然而，硬脂酸降低肝脏胆固醇和甘油三酯浓度，而棕榈酸降低肝脏甘油三酯浓度。硬脂酸再次降低了喂食胆固醇补充饮食的仓鼠的肝脏胆固醇浓度，而饮食饱和脂肪酸对其他脂质参数没有影响。在饲喂无胆固醇饮食的仓鼠中，硬脂酸和棕榈酸都能降低肝脏胆固醇的浓度，而血清胆固醇只有硬脂酸能降低。饲喂硬脂酸和棕榈酸的大鼠和仓鼠粪便中脂肪酸和中性类固醇的排泄量增加。当仓鼠被喂食高胆固醇饮食时，低密度脂蛋白（LDL）的分数分解代谢率仅在硬脂酸中较高，而当仓鼠被喂食无胆固醇饮食时，它不受影响。低密度脂蛋白受体蛋白的浓度不受一系列饱和脂肪酸的影响。在硬脂酸中，ADP诱导的血小板聚集程度和主动脉前列环素的产生降低。饱和脂肪酸对亚油酸在肝脏磷脂中的代谢有不同的影响。这些观察结果表明，不同的饱和脂肪酸对各种脂质参数有不同的影响。

Effects of dietary lauric, myristic, palmitic and stearic acids on lipid metabolism were investigated in rats and hamsters using interesterified fats. When rats were fed cholesterol-supplemented diets, these saturated fatty acids did not influence the concentration of serum lipids. However,stearic acid decreased the concentrations of hepatic cholesterol and triglyceride, whereas palmitic acid decreased hepatic triglyceride. Stearic acid again decreased the concentration of hepatic cholesterol in hamsters fed a cholesterol-supplemented diet, whereas dietary saturated fatty acids showed no effects on other lipid parameters. In hamsters fed a cholesterol-free diet, both stearic and palmitic acids decreased the concentrations of hepatic cholesterol, whereas serum cholesterol was reduced only by stearic acid. The increased fecal excretion of fatty acids and neutral steroids was observed on feeding stearic and palmitic acids in rats and hamsters. Fractional catabolic rate of low density lipoproteins (LDL) was higher only in stearic acid when hamsters were fed a high cholesterol diet, whereas it was not influenced when hamsters were fed a cholesterol-free diet. The concentration of LDL receptor protein was not altered by a series of saturated fatty acids. The extent of platelet aggregation induced by ADP and the production of aortic prostacyclin was lower in stearic acid in rats fed a cholesterol-supplemented diet. Saturated fatty acids appeared to be differently influence the metabolism of linoleic acid in liver phospholipids. These observations suggest that the different saturated fatty acids exert different effects on various lipid parameters.