RT Journal Article
SR Electronic
T1 Michaelis Constants for the Hydroxylation of Steroid Hormones and Drugs by Rat Liver Microsomes
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 163
OP 167
VO 1
IS 2
A1 R. KUNTZMAN
A1 D. LAWRENCE
A1 A. H. CONNEY
YR 1965
UL http://molpharm.aspetjournals.org/content/1/2/163.abstract
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.