Nagaoka S, Miyazaki H, Oda H, Aoyama Y, Yoshida A
Department of Agricultural Chemistry, Nagoya University, Japan.
J Nutr. 1990 Oct;120(10):1134-9. doi: 10.1093/jn/120.10.1134.
Excess dietary tyrosine (12%) caused hypercholesterolemia in male Wistar rats and significantly increased cytochrome P-450 and b5 contents. Bile flow and biliary output of total bile acids were significantly increased in rats fed this diet. Biliary output of cholesterol was not significantly altered, whereas that of taurocholic acid was significantly increased. Excess dietary tyrosine significantly decreased the fecal excretion of neutral steroids, whereas total steroid excretion was not significantly changed. The present results indicate that excess dietary tyrosine causes hypercholesterolemia without modifying the fecal total steroid excretion, thus supporting our previous hypothesis that stimulated synthesis of cholesterol is a main reason why excess dietary tyrosine leads to hypercholesterolemia.
过量的膳食酪氨酸（12%）导致雄性Wistar大鼠出现高胆固醇血症，并显著增加细胞色素P-450和b5的含量。喂食这种饮食的大鼠胆汁流量和总胆汁酸的胆汁输出量显著增加。胆固醇的胆汁输出量没有显著改变，而牛磺胆酸的胆汁输出量显著增加。过量的膳食酪氨酸显著降低了中性类固醇的粪便排泄量，而总类固醇排泄量没有显著变化。目前的结果表明，过量的膳食酪氨酸会导致高胆固醇血症，而不会改变粪便中总类固醇的排泄量，从而支持了我们之前的假设，即膳食酪氨酸过量导致高胆固醇血症的主要原因是刺激了胆固醇的合成。
