These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cholic acid biosynthesis: conversion of 5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol into 5beta-cholestane-3alpha,7alpha, 12alpha,24beta,25-pentol by human and rat liver microsomes.
    Author: Cheng FW, Shefer S, Dayal B, Tint GS, Setoguchi T, Salen G, Mosbach EH.
    Journal: J Lipid Res; 1977 Jan; 18(1):6-13. PubMed ID: 13134.
    Abstract:
    This paper describes the conversion of 5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol into 5beta-cholestane-3alpha,7alpha,12alpha,24beta,25-pentol by liver microsomes. A sensitive radioactive assay for measuring the formation of 5beta-cholestane-3alpha,7alpha,12alpha,24beta,25-pentol was developed. Optimal assay conditions for human and rat microsomal systems were established. A higher 24beta-hydroxylation activity was detected in rat than in human liver under the conditions employed. The hydroxylation of 5beta-cholestane-3alpha,7alpha,12alpha,25-tetrol by the rat liver microsomal fraction fortified with NADPH was stimulated about two-fold by administration of phenobarbital. Phenobarbital treatment also stimulated hydroxylations at C-23, C-24alpha, and C-26. Carbon monoxide markedly inhibited all side-chain hydroxylations. In contrast, side-chain hydroxylase activities were not affected in animals deprived of food for 48 hr. These results are consistent with a previously postulated cholic acid biosynthetic pathway involving 5beta-cholestane-3alpha,7alpha,12alpha,24beta,25-pentol as a key intermediate in man and in the rat.
    [Abstract] [Full Text] [Related] [New Search]