Ramirez H, Alejandre M J, Segovia J L, Garcia-Peregrin E
Lipids. 1981 Jul;16(7):552-4. doi: 10.1007/BF02535055.
The Arrhenius plots of hepatic and cerebral 3-hydroxy-3-methylglutaryl-CoA reductase activity were studied in neonatal chicks fed with a standard diet. Supplementation of the diet with 2% cholesterol from hatching has no effect on the thermal characteristics of the brain enzyme. The Arrhenius plot of brain reductase was practically similar to that found in control chicks. However, hepatic reductase was inhibited by cholesterol feeding. Dietary cholesterol increased the cholesterol/lipidic phosphorus molar ratio in liver microsomes, whereas no significant differences were observed in brain microsomes. These results are in agreement with the hypothesis that activity of hepatic reductase is regulated by the fluidity of microsomal membrane and show that cholesterol feeding does not alter the fluidity of microsomal membranes in neonatal chick brain having, thus, no effect on the thermal behavior of cerebral reductase.
研究了用标准饮食喂养的新生雏鸡肝脏和大脑中3-羟基-3-甲基戊二酰辅酶A还原酶活性的阿伦尼乌斯曲线。从孵化开始在饮食中添加2%的胆固醇对脑酶的热特性没有影响。脑还原酶的阿伦尼乌斯曲线实际上与对照雏鸡中的相似。然而，喂食胆固醇会抑制肝脏还原酶。饮食中的胆固醇增加了肝脏微粒体中胆固醇/脂质磷的摩尔比，而在脑微粒体中未观察到显著差异。这些结果与肝脏还原酶活性受微粒体膜流动性调节的假设一致，并表明喂食胆固醇不会改变新生雏鸡大脑微粒体膜的流动性，因此对脑还原酶的热行为没有影响。
