PT  - JOURNAL ARTICLE
AU  - R. KUNTZMAN
AU  - D. LAWRENCE
AU  - A. H. CONNEY
TI  - Michaelis Constants for the Hydroxylation of Steroid Hormones and Drugs by Rat Liver Microsomes
DP  - 1965 Sep 01
TA  - Molecular Pharmacology
PG  - 163--167
VI  - 1
IP  - 2
4099  - http://molpharm.aspetjournals.org/content/1/2/163.short
4100  - http://molpharm.aspetjournals.org/content/1/2/163.full
SO  - Mol Pharmacol1965 Sep 01; 1
AB  - The Michaelis constants (Km values) for the oxidative metabolism of progesterone, testosterone, and estradiol-17β by liver microsomes from adult male rats were determined. These values ranged from 1.6 x 10-5M to 4.9 x 10-5M. Previous studies have suggested that oxidative drug-metabolizing enzymes have steroids as normal body substrates. This concept is consistent with the results presented here indicating that the Km values for the oxidative metabolism of steroid hormones are about 10 times lower than the Km values for the metabolism of several drugs.