Kelley M J, Story J A
Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana.
Lipids. 1987 Dec;22(12):1057-9. doi: 10.1007/BF02536451.
In vivo regulation of hepatic HMG-CoA reductase (HMGR) (mevalonate:NADP+ oxidoreductase [acylating CoA]; EC 1.1.1.34] by phosphorylation/dephosphorylation has not been demonstrated. Rats were meal-fed semipurified diets; effects of inclusion of cholesterol (2%) or oat bran (15%) in a single meal on expressed (phosphorylated) and total (dephosphorylated) activities of HMGR were measured from 15 min to 4 hr after presentation of the meal. Expressed activity was not significantly altered in response to the control diet during the time periods examined, while total HMGR activity declined by 15 min and increased through 4 hr to an activity about 1.5 times control levels. Addition of cholesterol resulted in little change in expressed activity but a greater and more sustained reduction in total activity. Oat bran caused reductions in both total and expressed activities, which were maintained through 4 hr. Total HMGR activity was best correlated with apparent demand for cholesterol synthesis.
尚未证实通过磷酸化/去磷酸化对肝脏中3-羟基-3-甲基戊二酰辅酶A还原酶（HMGR）（甲羟戊酸：NADP⁺氧化还原酶[酰化辅酶A]；EC 1.1.1.34）进行体内调节。给大鼠喂食半纯化日粮；在喂食一餐含胆固醇（2%）或燕麦麸（15%）的食物后15分钟至4小时内，测定一餐中添加胆固醇（2%）或燕麦麸（15%）对HMGR的表达（磷酸化）活性和总（去磷酸化）活性的影响。在所研究的时间段内，对照日粮对表达活性没有显著影响，而总HMGR活性在15分钟时下降，4小时内增加至约为对照水平的1.5倍。添加胆固醇导致表达活性变化不大，但总活性下降幅度更大且更持久。燕麦麸使总活性和表达活性均降低，并持续4小时。总HMGR活性与胆固醇合成的表观需求最相关。
