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

我们研究了用牛跟腱和动脉制备的饲料喂养的大鼠的牛膳食蛋白质的生理重要性。将不含胆固醇的大鼠饲喂含20%酪蛋白的饲料（CON），与含15%酪蛋白和5%牛跟腱（AC）或动脉（AR）蛋白制剂的两种饲料（CON）饲喂4周。4周饲养结束时，AR饲喂组血清总胆固醇浓度和非高密度脂蛋白胆固醇水平显著低于CON组（P<0.05）。测定肝脏mRNA水平，AR饲喂组HMG-CoA还原酶mRNA水平显著低于CON组（P<0.05）， AC饲喂组有低于CON组的趋势。AC组大鼠肝脏总胆固醇浓度显著高于CON组（P<0.05）。在整个饲喂期内，AC和AR饲喂组血清甘油三酯（TG）浓度和脂肪酸合成酶（FAS） mRNA水平均显著低于CON组（P<0.05）。AC和AR饲喂组粪便中性固醇排泄量显著高于CON组（P<0.05）。本研究结果表明，某些牛饲粮蛋白质具有与饲粮纤维相似的功能，通过促进粪便中性固醇排泄和抑制肝脏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饲喂组牛蛋白饲粮的低血脂浓度有影响。

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.