PMID: 7017048Feb 1, 1981Paper

Assay of intermediates in bile acid biosynthesis using isotope dilution--mass spectrometry: hepatic levels in the normal state and in cerebrotendinous xanthomatosis.

Journal of Lipid Research
I BjörkhemJ I Pedersen

Abstract

The synthesis of 2H4-labeled 5 beta-cholestane-3 alpha, 7 alpha-diol, 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol, 7 alpha-hydroxy-4-cholesten-3-one, and 7 alpha,12 alpha-dihydroxy-4-cholesten-3-one is described. A mixture of these compounds, together with 2H3-labeled 5-cholestene-3 beta, 7 alpha-diol, was added to extracts of different subcellular fractions of liver. After purification by high performance liquid chromatography and conversion into trimethylsilyl ethers, the amounts of different endogenous unlabeled steroids were determined by selected ion monitoring. In normal liver, the concentration of 5-cholestene-3 beta, 7 alpha-diol (about 0.1-0.2 microgram/ml protein) was higher than the concentration of the other steroids (about 0.01-0.05 microgram/mg protein). The concentration of the different steroids was highest in the microsomal fraction of the liver homogenate. In a liver sample from a patient with cerebrotendinous xanthomatosis (CTX), the amounts of the 12 alpha-hydroxylated steroids were considerably higher than in the normal liver. The levels of 7 alpha-hydroxy-4-cholesten-3-one and 5 beta-cholestane-3 alpha, 7 alpha-diol were similar or only slightly higher than in the liver of the control patients. The co...Continue Reading

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.