Aoyama Y, Amano N, Yoshida A
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
Lipids. 1999 Jun;34(6):583-9. doi: 10.1007/s11745-999-0402-8.
Feeding a diet with excess cystine to rats resulted in hypercholesterolemia. To understand the mechanism of the hypercholesterolemia, cholesterol synthesis and degradation, bile acid content of bile, and fecal steroids were determined. The in vivo incorporation of tritiated water into hepatic cholesterol, and activity of hepatic 3-hydroxy-3-methylglutaryl-CoA reductase in rats fed a high-cystine diet were significantly higher than those in rats fed a control diet. The activity of hepatic cholesterol 7 alpha-hydroxylase was similar between two groups. Little effect of cystine supplementation was found on fecal sterol excretion although there were some changes in biliary excretion of cholic acid derivatives. These results indicate that hypercholesterolemia caused by feeding of a high-cystine diet may be due to the stimulation of hepatic cholesterol synthesis.
给大鼠喂食含过量胱氨酸的饮食会导致高胆固醇血症。为了解高胆固醇血症的机制，对胆固醇的合成与降解、胆汁中的胆汁酸含量以及粪便类固醇进行了测定。喂食高胱氨酸饮食的大鼠体内，氚水掺入肝胆固醇的量以及肝3-羟基-3-甲基戊二酰辅酶A还原酶的活性显著高于喂食对照饮食的大鼠。两组之间肝胆固醇7α-羟化酶的活性相似。尽管胆酸衍生物的胆汁排泄有一些变化，但补充胱氨酸对粪便固醇排泄的影响很小。这些结果表明，喂食高胱氨酸饮食引起的高胆固醇血症可能是由于肝胆固醇合成受到刺激所致。
