A preliminary investigation of the products of the metabolism of testosterone by rat liver in vitro

Abstract

The metabolism of testosterone by rat-liver mince in vitro was studied at concentrations ensuring aqueous solution of the hormone and under conditions favoring 17-ketosteroid formation. Testosterone was incubated in phosphate buffer (pH 7.8) supplemented with diphospho-pyridine nucleotide and nicotinamide, but in the absence of heavy metals. At least 20% of the substrate is converted into androst-4-ene-3:17-dione. Enzymic transformation into unidentified polar keto-steroids accounts for a large fraction of the incubated hormone. Hy-droxylation reactions are postulated to explain their formation. Andros-terone, 3 alpha-hydroxy-5 beta-androstan-17-one, and residual testosterone were not detected in the extracts. Incubation of (4-C14) testos-terone at pH 7.4 has confirmed these findings.