In vitro metabolism of 7 alpha-methyl-19-nortestosterone by rat liver, prostate, and epididymis

Abstract

The in vitro metabolism of 7 alpha-methyl-19-nortestosterone (7 alpha-methyl-3-oxo-estr-4-ene-17 beta-ol) was investigated in male rat liver, ventral prostate, and epididymis. Three metabolites were recovered from the liver incubation: 7 alpha-methyl-estr-4-ene-3,17-dione, 7 alpha-methyl-5 beta-estrane-3,17 beta-diol, and 7 alpha-methyl-3-oxo-estr-4-ene-16,17 beta-diol, whereas prostate and epididymis did not perceptibly metabolize the steroid. The kinetics of metabolism in liver differed significantly from those of testosterone or 19-nortestosterone. About 85% of the 7 alpha-methyl-19-nortestosterone added was recovered at the end of 30 min of incubation. We conclude that the androgenic potency of 7-alpha-methyl-19-nortestosterone is not dependent on its further conversion to 5 alpha-dihydro-metabolites.