González-Pacanowska D, Marco C, Garcia-Martinez J, Garcia-Peregrin E
Biochim Biophys Acta. 1986 Feb 28;875(3):605-9. doi: 10.1016/0005-2760(86)90083-4.
The response of mevalonate kinase, mevalonate-5-phosphate kinase and mevalonate-5-pyrophosphate decarboxylase of chick liver to different dietary situations has been investigated. Fasting inhibited mevalonate kinase and mevalonate-5-pyrophosphate decarboxylase activities, while mevalonate-5-phosphate kinase remained practically unaltered. Refeeding after 72 h of starvation restored mevalonate kinase activity to normal levels after 120 h of refeeding. Likewise, decarboxylase activity reached normal levels at 72 h of refeeding the standard diet and slightly supranormal levels after 120 h. In addition, the sequential response of the three enzymes to a high cholesterol diet was followed throughout a 120 h period. Feeding a 5% cholesterol diet to 13-day-old chicks previously fed with a standard diet from hatching reduced considerably the activity of mevalonate-5-pyrophosphate decarboxylase, while the kinases were less affected. The present results support the idea of a coordinate regulation of the enzymes implied in cholesterol biosynthesis and suggest that mevalonate-5-pyrophosphate decarboxylase may play a significant role in this regulation.
研究了雏鸡肝脏中甲羟戊酸激酶、甲羟戊酸-5-磷酸激酶和甲羟戊酸-5-焦磷酸脱羧酶对不同饮食情况的反应。禁食抑制了甲羟戊酸激酶和甲羟戊酸-5-焦磷酸脱羧酶的活性，而甲羟戊酸-5-磷酸激酶活性基本未变。饥饿72小时后重新喂食，在重新喂食120小时后甲羟戊酸激酶活性恢复到正常水平。同样，脱羧酶活性在重新喂食标准饮食72小时时达到正常水平，在120小时后略高于正常水平。此外，在120小时内跟踪了这三种酶对高胆固醇饮食的顺序反应。给自孵化起就喂食标准饮食的13日龄雏鸡喂食5%胆固醇饮食，可显著降低甲羟戊酸-5-焦磷酸脱羧酶的活性，而激酶受影响较小。目前的结果支持胆固醇生物合成中相关酶协同调节的观点，并表明甲羟戊酸-5-焦磷酸脱羧酶可能在这种调节中起重要作用。
