大豆蛋白对高脂饲料喂养大鼠固醇调节元件结合蛋白基因表达的影响

目的探讨大豆蛋白在正常饮食和高脂饮食状态下对大鼠脂代谢相关固醇调节元件结合蛋白(SREBP)基因表达水平的影响。方法 48只清洁级SD大鼠,按体重随机分为4组,分别喂饲含酪蛋白和大豆蛋白的正常饲料和高脂饲料28d后,脱颈椎处死动物,检测激素指标及基因表达水平。结果大豆蛋白组大鼠血清胰岛素水平和胰岛素/胰高血糖素比值显著低于酪蛋白组(P<0.05);大豆蛋白高脂组大鼠血清胰岛素水平显著低于酪蛋白高脂组(P<0.05);大豆蛋白组和大豆蛋白高脂组大鼠肝脏SREBP-1,2基因表达均分别显著低于酪蛋白组和酪蛋白高脂组(P<0.05);大豆蛋白组和大豆蛋白高脂组大鼠肝脏SREBP-1蛋白表达明显低于酪蛋白组和酪蛋白高脂组(P<0.05)。结论大豆蛋白可能通过影响胰岛素进而影响SREBP-1基因表达来调节血脂水平。

Effect of soy protein on expression of SREBP-1 in rats

Objective To explore the effects of soy protein on the expression of SREBP-1,2 in rats feeding normal and high-fat diet.Methods Forty eight Sprague-Dawley SPF class rats were randomly divided into 4 groups matched by body weight,soy protein group,casein group,soy protein-high fat group,casein-high fat group.The experiment diets were fed for 28 d.Then the rats were sacrificed off cervical,determined serum levels of homone and the level of gene expression.Results The concentration of serum insulin and the ratio of insulin/glucagon in the soy protein group were significantly lower than that of the casein group((54.1±10.7) vs(63.5±16.9) pmol/L,P<0.05,(2.33±0.75) vs(3.21±1.41),P<0.05),the concentration of serum insulin and the ratio of insulin/glucagon in the soy protein high-fat group were significantly lower than that of the casein high-fat group((46.3±9.6) vs(50.4±10.1)pmol/L,P<0.05,(1.53±0.72) vs(2.92±1.23),P<0.05).The expression of SREBP-1,2 in soy protein group and soy protein high-fat group were significantly lower than that in casein group and casein high-fat group.The protein expression of SREBP-1 in soy protein group and soy protein high-fat group were significantly lower than that in casein group and casein high-fat group.Conclusion Dietary soy protein intake may modulate serum lipid levels through influence the insulin level then infulence the expression of SREBP-1,2 mRNA.