Effects ofresistantproleins oflivestock, bovine Achilles' tendons and arteries, on lipidmettholism in rats.

我们研究了牛饲料蛋白质的生理重要性，在大鼠饲养的饮食准备从牛跟腱和动脉。大鼠喂食无胆固醇饮食与20%酪蛋白饮食（CON），与两种饮食含有15%酪蛋白和5%的牛跟腱（AC）或动脉（AR）蛋白制剂4周。4周喂养结束时，AR组血清总胆固醇和非HDL胆固醇水平显著低于CON组（P<0.05）。结果表明，AR组HMG-CoA还原酶mRNA水平显著低于CON组（P<0.05），AC组HMG-CoA还原酶mRNA水平有降低趋势。AC组大鼠肝脏总胆固醇浓度显著高于CON组（P<0.05）。与对照组相比，AC组和AR组的血清甘油三酯（TG）浓度和脂肪酸合成酶（FAS）mRNA水平在整个饲养期间均显著降低（P<0.05）。与CON组相比，AC和AR饲喂组的粪便中性固醇排泄显著（P<0.05）更高。本研究结果表明，某些牛饲料蛋白具有与膳食纤维相似的功能，即通过促进粪便中性固醇的排泄和抑制肝脏中的脂质合成来降低血清脂质浓度。此外，AR和AC中有利的氨基酸组成也可能对牛蛋白质饮食喂养组中的低血浆脂质浓度产生影响。

We examined the physiological importance of bovine dietary proteins in rats fed diets prepared from bovine Achilles' tendons and arteries. Rats were fed a cholesterol-free diet with 20% casein diet (CON), in comparison with two diets containing 15% casein and 5% of either bovine Achilles' tendons (AC) or arteries (AR) protein preparations for 4 weeks. The serum total cholesterol concentration and non-HDL cholesterol level in the AR fed group were significantly lower (P<0.05) than those in the CON group at the end of the 4 week feeding period. The hepatic mRNAs were measured, and the HMG-CoA reductase mRNA level was significantly lower (P<0.05) in AR fed group compared to CON group, and that in AC fed group tended to be lower compared to CON group. Total hepatic cholesterol concentration, in rats fed AC was significantly (P<0.05) higher than in the CON group. The serum triglyceride (TG) concentration and fatty acid synthase (FAS) mRNA level in AC and AR fed groups were significantly lower (P<0.05) compared to the CON group through out the feeding period. Faecal neutral sterol excretion was significantly (P<0.05) higher in the AC and AR fed groups compared to the CON group. The results of this study demonstrate that the some bovine dietary proteins have similar functions as dietary fibres which lowered the serum lipid concentration by enhancing faecal neutral sterol excretion, and suppressing lipid synthesis in the liver. Moreover, favourable amino acid compositions in AR and AC may also have an effect on low plasma lipid concentration in bovine protein diets fed groups.