Tsai A C
J Nutr. 1977 Apr;107(4):546-51. doi: 10.1093/jn/107.4.546.
A series of experiments was conducted to elucidate the mechanism by which cholesterol feeding decreases serum insulin levels in rats and to determine the effect of this reduced insulin level on glucose metabolism. Rats were fed a casein-sucrose-soybean oil basal diet or this basal diet supplemented with 1% cholesterol (dissolved in hot oil) for periods longer than 30 days. Cholesterol feeding resulted in a decrease in serum insulin concentrations, although the decrease was not always significant. Cholesterol feeding did not affect fasting blood glucose levels, glucose tolerance, glucose-induced insulin release, pancreatic insulin content, in vivo insulin sensitivity, or in vitro glucose utilization in diaphragm and adipose tissue, but it significantly elevated the activity of liver glutathione-insulin transhydrogenase. On a per liver basis, the activity of this enzyme was approximately doubled. Results of this study suggest that cholesterol feeding has no significant effect on glucose utilization, but it can lead to a decrease in serum insulin concentration, probably by increasing the rate of insulin degradation in the liver.
进行了一系列实验，以阐明喂食胆固醇降低大鼠血清胰岛素水平的机制，并确定这种降低的胰岛素水平对葡萄糖代谢的影响。给大鼠喂食酪蛋白 - 蔗糖 - 大豆油基础日粮，或在该基础日粮中添加1%胆固醇（溶于热油中），持续30多天。喂食胆固醇导致血清胰岛素浓度降低，尽管这种降低并不总是显著的。喂食胆固醇不影响空腹血糖水平、葡萄糖耐量、葡萄糖诱导的胰岛素释放、胰腺胰岛素含量、体内胰岛素敏感性或膈肌和脂肪组织的体外葡萄糖利用，但它显著提高了肝脏谷胱甘肽 - 胰岛素转氢酶的活性。以每肝脏计算，这种酶的活性大约增加了一倍。本研究结果表明，喂食胆固醇对葡萄糖利用没有显著影响，但可能通过增加肝脏中胰岛素的降解速率导致血清胰岛素浓度降低。
