Brandsch Corinna, Shukla Anjali, Hirche Frank, Stangl Gabriele I, Eder Klaus
Institute of Nutritional Sciences, Martin-Luther-University Halle-Wittenberg, Halle/Saale, Germany.
Nutrition. 2006 Nov-Dec;22(11-12):1162-70. doi: 10.1016/j.nut.2006.06.009. Epub 2006 Sep 15.
We assessed the effect of dietary proteins isolated from beef, pork, and turkey meat on concentrations of cholesterol and triacylglycerols in plasma, lipoproteins, and liver and the composition of the microsomal membrane (fatty acids, phosphatidylcholine/phosphatidylethanolamine ratio) compared with that of casein and soy protein in rats.
Five groups of 12 rats each were fed semisynthetic diets for 20 d that contained 200 g/kg of proteins isolated from beef, pork, or turkey meat or, as controls, casein or soy protein.
Rats fed beef, pork, or turkey proteins did not differ in cholesterol concentrations of plasma, lipoproteins, and liver and in composition of microsomal membrane from rats fed the casein diet. All groups fed a protein from an animal source had higher very low-density lipoprotein (VLDL) and liver cholesterol concentrations than did rats fed soy protein. However, rats fed pork protein had lower concentrations of triacylglycerols in liver, plasma, and VLDL and lower mRNA concentrations of sterol regulatory element binding protein-1 and glucose-6-phosphate dehydrogenase than did rats fed casein. However, concentrations of plasma and VLDL triacylglycerols in rats fed pork protein were not as low as those observed in rats fed soy protein.
Proteins isolated from beef, pork, or turkey meat do not differ from casein in their effects on cholesterol metabolism. Pork protein decreases plasma triacylglycerol concentrations compared with casein but not compared with soy protein. The triacylglycerol-lowering effect of pork protein compared with casein is suggested to be caused by decreased hepatic fatty acid synthesis.
我们评估了从牛肉、猪肉和火鸡肉中分离出的膳食蛋白质对大鼠血浆、脂蛋白和肝脏中胆固醇及三酰甘油浓度的影响，以及与酪蛋白和大豆蛋白相比，微粒体膜的组成（脂肪酸、磷脂酰胆碱/磷脂酰乙醇胺比值）。
将五组大鼠，每组12只，喂食半合成饲料20天，饲料中含有200 g/kg从牛肉、猪肉或火鸡肉中分离出的蛋白质，或作为对照的酪蛋白或大豆蛋白。
喂食牛肉、猪肉或火鸡肉蛋白质的大鼠，其血浆、脂蛋白和肝脏中的胆固醇浓度以及微粒体膜的组成与喂食酪蛋白饲料的大鼠没有差异。所有喂食动物源蛋白质的组，其极低密度脂蛋白（VLDL）和肝脏胆固醇浓度均高于喂食大豆蛋白的大鼠。然而，喂食猪肉蛋白的大鼠肝脏、血浆和VLDL中的三酰甘油浓度低于喂食酪蛋白的大鼠，固醇调节元件结合蛋白-1和葡萄糖-6-磷酸脱氢酶的mRNA浓度也较低。但是，喂食猪肉蛋白的大鼠血浆和VLDL中的三酰甘油浓度并不像喂食大豆蛋白的大鼠那样低。
从牛肉、猪肉或火鸡肉中分离出的蛋白质对胆固醇代谢的影响与酪蛋白没有差异。与酪蛋白相比，猪肉蛋白可降低血浆三酰甘油浓度，但与大豆蛋白相比则不然。与酪蛋白相比，猪肉蛋白降低三酰甘油的作用可能是由于肝脏脂肪酸合成减少所致。
