Gustafsson J
Lipids. 1980 Feb;15(2):113-21. doi: 10.1007/BF02533886.
Conversion of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid into 3 alpha, 7 alpha, 12 alpha 24-tetrahydroxy-5 beta-cholestanoic and cholic acids was catalyzed either by the mitochondrial fraction fortified with coenzyme A, ATP, MgCl2 and NAD or by the combination of microsomal fraction and 100,000 x g supernatant fluid fortified with coenzyme A, ATP and nad. 24-hydroxylation and formation of cholic acid occurred at similar rates with the 25R- and the 25S-forms of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid. The 25R- and 25S-forms of 3 alpha, 7 alpha, 12 alpha-trihydroxy- and 3 alpha, 7 alpha, 12 alpha, 24-tetrahydroxy-5 beta-cholestanoic acids were administered to bile fistula rats. Labeled cholic acid was isolated from the bile. The initial specific radioactivity of cholic acid was higher and the disappearance of radioactivity more rapid after administration of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5 beta-cholestanoic acid than of 3 alpha, 7 alpha, 12 alpha, 24-tetrahydroxy-5 beta-cholestanoic acid. The findings are discussed in relation to the assumed pathway for side chain cleavage in cholic acid biosynthesis.
3α,7α,12α - 三羟基 - 5β - 胆甾烷酸转化为3α,7α,12α,24 - 四羟基 - 5β - 胆甾烷酸和胆酸，可由添加辅酶A、ATP、MgCl₂和NAD的线粒体部分催化，也可由添加辅酶A、ATP和NAD的微粒体部分与100,000×g上清液的组合催化。3α,7α,12α - 三羟基 - 5β - 胆甾烷酸的25R - 和25S - 形式进行24 - 羟基化和胆酸形成的速率相似。将3α,7α,12α - 三羟基 - 5β - 胆甾烷酸和3α,7α,12α,24 - 四羟基 - 5β - 胆甾烷酸的25R - 和25S - 形式给予胆管瘘大鼠。从胆汁中分离出标记的胆酸。给予3α,7α,12α - 三羟基 - 5β - 胆甾烷酸后，胆酸的初始比放射性较高，放射性消失更快，高于给予3α,7α,12α,24 - 四羟基 - 5β - 胆甾烷酸的情况。结合胆酸生物合成中假定的侧链裂解途径对这些发现进行了讨论。
