大豆蛋白和高钙摄入对高血胆固醇模型大鼠血脂水平的影响

目的探讨膳食大豆蛋白和/或高钙摄入对高血胆固醇模型大鼠血浆胆固醇及有关血脂指标的影响.方法用含5%猪油、1%胆固醇和0.25%胆碱的高脂饲料喂饲健康Wistar雌性大鼠,经14d诱发高血胆固醇以后,测血浆总胆固醇(TC),总甘油三酯(TG),高密度脂蛋白胆固醇(HDL-C)和载脂蛋白B(ApoB100)的浓度.然后,按体重和血浆胆固醇浓度将动物均衡分为4组,以2×2析因设计,分别喂饲含有酪蛋白和大豆分离蛋白及正常钙(0.59%)和高钙水平(1.12%)的纯合成高脂饲料.经21d喂养后,采血,测定指标同前.实验结果用SPSS统计软件进行方差分析.结果经14d诱导高血脂后,实验模型大鼠的TC水平为(4.10±1.11)mmol/L(n=24),而喂饲正常饲料的阴性对照鼠仅为(1.92±0.28)mmol/L(n=8),升高了2.14倍.又经21d喂饲含有处理因素的饲料后,酪蛋白组,酪蛋白加钙组,大豆蛋白组和大豆蛋白加钙组大鼠的TC水平分别为(10.56±2.74,7.99±2.19,5.48±0.51和6.81±0.98)mmol/L;ApoB100为(0.46±0.14,0.31±0.12,0.17±0.07和0.21±0.05)g/L.同酪蛋白组相比,其他3组动物的TC和ApoB100浓度显著降低.而各组间TG和HDL-C的变化均无显著性.结论膳食大豆蛋白和/或高钙摄入均可降低高血胆固醇模型大鼠的TC和ApoB100浓度,但对TG和HDL-C的作用不明显.大豆蛋白是这种作用的主要因素,但同时存在大豆蛋白和高钙摄入的相互作用.膳食大豆蛋白和高钙摄入的降血胆固醇机制还需要进一步探讨和研究.

Effect of soybean protein and high calcium intake on the concentration of serum lipids in hypercholesterolemic rats

OBJECTIVE: To investigate the effects of dietary soybean protein or/and high calcium intake on the concentration of serum total cholesterol (TC) and serum lipids in hypercholesterolemic rats. METHODS: Following 14 days of inducing the hypercholesterolemia model successfully, 24 female rats were fed 4 experimental diets contained 20% of protein each from either casein or soybean protein and either a normal or high concentration of calcium (0.59% and 1.12%) in a 2 x 2 factorial design. RESULTS: After the experimental diets had been fed for 21 days, TC was (10.56 +/- 2.74, 7.99 +/- 2.19, 5.48 +/- 0.51 and 6.81 +/- 0.98) mmol/L in the rats fed diets containing casein and normal concentration of calcium, casein and high concentration of calcium, soybean, protein and normal concentration of calcium, and soybean protein and high concentration of calcium, respectively. According, Serum apolipoprotein B100(ApoB100) was (0.46 +/- 0.14, 0.31 +/- 0.12, 0.17 +/- 0.07, and 0.21 +/- 0.05) g/L, respectively. Comparing with the rats in casein group, the TC and ApoB100 of the rats in other 3 groups were significantly low (P < 0.05). Whereas, the changes of TG and HDL-C were not significant in these rats. CONCLUSIONS: Dietary soybean protein or/and high calcium intake lower TC in hypercholesterolemic rats and there is an interactive effect of these two dietary factors on lowering TC. Further researches are needed for explaining the possible mechanism of soybean protein and high calcium intake on lowering TC.