Polyunsaturated fatty acids up-regulate hepatic scavenger receptor B1 (SR-BI) expression and HDL cholesteryl ester uptake in the hamster.
Polyunsaturated fatty acids up-regulate hepatic scavenger receptor B1 (SR-BI) expression and HDL cholesteryl ester uptake in the hamster.
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发表时间：
1999-08
影响因子：
6.5
通讯作者：
D. Spady;D. Kearney;H. Hobbs
中科院分区：
文献类型：
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作者：
D. Spady;D. Kearney;H. Hobbs
与富含饱和脂肪酸的饮食相比，富含多不饱和脂肪酸的饮食可降低血浆高密度脂蛋白胆固醇浓度。我们在仓鼠中研究了这种作用的机制基础，并试图确定高多不饱和脂肪饮食导致的血浆高密度脂蛋白胆固醇浓度降低是否与胆固醇逆向转运的减少有关。饲喂富含多不饱和脂肪酸或饱和脂肪酸的半合成饲料6周。然后，我们确定了这些饮食对以下参数的影响：1)肝脏清除率受体B1 (SR-BI) mRNA和蛋白质水平，2)肝脏高密度脂蛋白胆固醇酯摄取率，以及3)肝外组织（从头合成，低密度脂蛋白和高密度脂蛋白）获取胆固醇的速度，作为胆固醇逆向运输速度的衡量标准。与饱和脂肪酸相比，饮食中的多不饱和脂肪酸上调肝脏SR-BI表达约50%，并增加高密度脂蛋白胆固醇酯向肝脏的转运；结果，血浆高密度脂蛋白胆固醇酯浓度降低。虽然饮食中的多不饱和脂肪酸增加了肝脏高密度脂蛋白胆固醇酯的摄取，降低了血浆高密度脂蛋白胆固醇浓度，但胆固醇含量和肝外组织胆固醇获取率（通过重新合成和脂蛋白摄取）没有变化。这些研究表明，在饮食中用多不饱和脂肪酸替代饱和脂肪酸会增加SR-BI表达，降低血浆高密度脂蛋白胆固醇酯浓度，但不影响胆固醇的逆向转运。
Diets rich in polyunsaturated fatty acids lower plasma HDL cholesterol concentrations when compared to diets rich in saturated fatty acids. We investigated the mechanistic basis for this effect in the hamster and sought to determine whether reduced plasma HDL cholesterol concentrations resulting from a high polyunsaturated fat diet are associated with a decrease in reverse cholesterol transport. Animals were fed semisynthetic diets enriched with polyunsaturated or saturated fatty acids for 6 weeks. We then determined the effect of these diets on the following parameters: 1) hepatic scavenger receptor B1 (SR-BI) mRNA and protein levels, 2) the rate of hepatic HDL cholesteryl ester uptake, and 3) the rate of cholesterol acquisition by the extrahepatic tissues (from de novo synthesis, LDL and HDL) as a measure of the rate of reverse cholesterol transport. Compared to saturated fatty acids, dietary polyunsaturated fatty acids up-regulated hepatic SR-BI expression by approximately 50% and increased HDL cholesteryl ester transport to the liver; as a consequence, plasma HDL cholesteryl ester concentrations were reduced. Although dietary polyunsaturated fatty acids increased hepatic HDL cholesteryl ester uptake and lowered plasma HDL cholesterol concentrations, there was no change in the cholesterol content or in the rate of cholesterol acquisition (via de novo synthesis and lipoprotein uptake) by the extrahepatic tissues.These studies indicate that substitution of polyunsaturated for saturated fatty acids in the diet increases SR-BI expression and lowers plasma HDL cholesteryl ester concentrations but does not affect reverse cholesterol transport.