Balasubramaniam S, Mitropoulos K A, Myant N B
Biochim Biophys Acta. 1975 Jul 22;398(1):172-7. doi: 10.1016/0005-2760(75)90180-0.
The rates of incorporation of (14C) cholesterol into cholesteryl esters and 5-cholestene-3beta,7alpha-diol (7alpha-hydroxycholesterol) by rat liver microsomes, measured under conditions in which esterification and 7alpha-hydroxylation are varied independently, indicated that cholesterol is the substrate for cholesterol 7alpha-hydroxylase. The specific activities of cholesteryl esters and 7alpha-hydroxycholeste ol in incubations of microsomes labelled with (14C)cholesterol in vitro or in vivo suggest that 7alpha-hydroxycholesterol and esterified cholesterol are not derived from the same pool of free cholesterol.
在酯化作用和7α-羟基化作用可独立变化的条件下，测定了大鼠肝脏微粒体将（14C）胆固醇掺入胆固醇酯和5-胆甾烯-3β，7α-二醇（7α-羟基胆固醇）的速率，结果表明胆固醇是胆固醇7α-羟化酶的底物。体外或体内用（14C）胆固醇标记的微粒体孵育时，胆固醇酯和7α-羟基胆固醇的比活性表明，7α-羟基胆固醇和酯化胆固醇并非来自同一游离胆固醇池。
