不同来源的蛋白质对大鼠血脂水平的影响

Effect of different dietary protein source and protein level on serum lipids profile in rats

目的研究雄性大鼠在长期摄入不同来源和含量的蛋白质饲料后,其血脂水平及各血脂比值的变化。方法将断乳雄性大鼠按体重随机分为4组(n=15),分别给予牛奶粉(HM组和LM组)或大豆粉/蛋清粉(HS组和LS组)为蛋白质来源的饲料(每种饲料中总蛋白质含量分别为18%和9%),持续喂养20周后,检测各组大鼠血清中血脂水平,并计算各类血脂的比值。结果在各实验组中,HM组大鼠血清总胆固醇(TC)和高密度脂蛋白胆固醇(HDL-C)水平最高(P<0.05),TC/HDL-C比值最低(P<0.05);HS组大鼠甘油三酯(TG)水平最低(P<0.05)。HS与HM组的TG/HDL-C比值低于LS与LM组(P<0.05)。LS与HS组低密度脂蛋白胆固醇(LDL-C)水平和LDL-C/HDL-C比值均低于LM与HM组(P<0.05)。结论给予高剂量大豆粉来源蛋白质,可以显著降低大鼠的TG水平;若长期给予高剂量牛奶粉作为蛋白质来源,可明显升高大鼠血清胆固醇总体水平。

Objective The aim of this study was to evaluate the effect of dietary protein source and protein level on serum lipids in male rats. Methods Wistar weaning male rats were assigned to four groups （15 rats in each group） according to their original body weight. The effects of two kinds of dietary protein with two different levels, including low cow milk （LM, 9% ）, high cow milk （HM, 18% ）, low soybean and egg white （LS, 9% ） , and high soybean and egg white （HS, 18% ） diets, were observed. Each group was provided with one of four diets for 20 weeks. Serum lipids were tested and the ratio of lipid were calculated. Results Serum TC and HDL-C were the highest and TC/HDL-C was the lowest in HM group; serum TG in HS group was the lowest. The ratio of TG/HDL-C in HS and HM group was lower than LS and LM group. Compared with LM and HM groups, serum LDL-C and LDL-C/HDL-C was lower in LS and HS group. Conclusion Long-term intake of protein from soybean and egg white, serum TG level may be significantly lower, which may reduce the risk of atherosclerosis. There was a trend of rising serum cholesterol level in rats fed with protein from cow milk for a long time.