Hevia P, Kari F W, Ulman E A, Visek W J
J Nutr. 1980 Jun;110(6):1224-30. doi: 10.1093/jn/110.6.1224.
Liver and serum lipid conentrations were studied in rats fed 7.5, 15 and 30% casein supplemented with 0, 2.5 and 5% lysine. Increasing dietary casein from 7.5 to 15% increased serum total lipids, triglycerides and cholesterol. When casein was increased from 15 to 30%, there was a further increase in plasma cholesterol and a decrease in triglycerides. Rats fed 7.5% casein alone developed fatty livers. Adding 5% lysine to 15% casein caused fatty livers but prevented them with casein at 7.5%. Lysine had no effect on total liver lipids with casein at 30%. The lipids of the fatty livers with 7.5% casein or with lysine were similar in composition. In both cases liver triglycerides increased fourfold and cholesterol twofold. Phospholipids remained unchanged and liver glycogen decreased. Excess dietary lysine did not change serum lipids ang glucose significantly. The data show that excess lysine caused changes in lipid metabolism which varied with the quantity of casein fed. The hypercholesterolemia with casein feeding seen by others appears unrelated to the high lysine content of this protein.
对喂食含0%、2.5%和5%赖氨酸的7.5%、15%和30%酪蛋白的大鼠的肝脏和血清脂质浓度进行了研究。将膳食酪蛋白从7.5%增加到15%会增加血清总脂质、甘油三酯和胆固醇。当酪蛋白从15%增加到30%时，血浆胆固醇进一步增加，甘油三酯减少。仅喂食7.5%酪蛋白的大鼠出现了脂肪肝。在15%酪蛋白中添加5%赖氨酸会导致脂肪肝，但在7.5%酪蛋白时可预防。赖氨酸对30%酪蛋白时的肝脏总脂质没有影响。含7.5%酪蛋白或含赖氨酸的脂肪肝的脂质组成相似。在这两种情况下，肝脏甘油三酯增加了四倍，胆固醇增加了两倍。磷脂保持不变，肝糖原减少。过量的膳食赖氨酸对血清脂质和葡萄糖没有显著影响。数据表明，过量赖氨酸会导致脂质代谢发生变化，这种变化因喂食的酪蛋白量而异。其他人所观察到的酪蛋白喂养引起的高胆固醇血症似乎与该蛋白质的高赖氨酸含量无关。
