Related Experiment Video
Updated: Jul 17, 2026

Determination of Fatty Acid Oxidation and Lipogenesis in Mouse Primary Hepatocytes
Published on: August 27, 2015
Bile acid synthesis during development. Mitochondrial 12 alpha-hydroxylation in human fetal liver
Abstract:
Hydroxylation of 5 beta-[7 beta-3H]cholestane-3 alpha, 7 alpha-diol was studied in mitochondrial preparations from human fetal livers. The livers were obtained at legal abortions between weeks 14 and 24. In addition to hydroxylation in the 26-position, 5 beta-cholestane-3 alpha, 7 alpha-diol was hydroxylated in the 12 alpha-position. In one experiment, mitochondrial protein was solubilized and partially purified. Material with such chromatographic properties as those of cytochrome P450 showed 12 alpha-hydroxylase activity when combined with adrenodoxin and adrenodoxin reductase from bovine adrenal mitochondria. Because adrenodoxin and adrenodoxin reductase are components specific for mitochondrial hydroxylase systems, the results exclude microsomal contamination as the origin of this 12 alpha-hydroxylase activity. Further, there was no hydroxylase activity when NADPH-cytochrome P450 reductase from rat liver microsomes was added instead of adrenodoxin and adrenodoxin reductase. The microsomal fraction of fetal liver was also shown to possess 12 alpha-hydroxylase activity. Microsomal and mitochondrial hydroxylase activities per milligram of protein towards 5 beta-cholestane-3 alpha, 7 alpha-diol were of the same order of magnitude. The occurrence of an efficient sterol nucleus hydroxylase activity in liver mitochondria appears to be unique for fetal liver.
More Related Videos
Related Concept Videos
Animal Mitochondrial Genetics
Overview of Fatty Acid Metabolism
Fatty acids are catabolized in a process called beta-oxidation, which takes place in the matrix of the mitochondria and converts their fatty acid chains into two-carbon units of acetyl groups. The acetyl...
Phase I Reactions: Oxidation of Aliphatic and Aromatic Carbon-Containing Systems
Oxidation reactions are fundamental in aromatic carbon-containing systems. An example is the hydroxylation of phenobarbital, a process that transforms it into...
Phase II Reactions: Acetylation Reactions
The substrates for acetylation are typically drugs or their metabolites with an amino, sulfonamide, or hydrazine functional group. Acetylation can occur at several points in the drug molecule, including primary, secondary, and...
Pharmacokinetics in Pediatric Patients: Drug Metabolism
Jaundice

