THE METABOLISM OF TESTOSTERONE BY TISSUE FROM NORMAL AND NEOPLASTIC MOUSE BREAST

Abstract

SUMMARY The qualitative and quantitative metabolism of testosterone in vitro by normal and neoplastic breast tissues of BR6 mice has been investigated. These tissues contain a Δ4-5α steroid reductase, 3-oxosteroid reductase and 17β-hydroxysteroid oxidoreductase. Qualitatively, the pregnancy-dependent and independent tumours differ in that the latter produce androst-4-ene-3α,17β-diol (androstenediol) whereas the former do not. This metabolite could not be detected in incubations with normal mammary tissue from pregnant mice. In general, tumours were more active than normal tissue from pregnant animals. No conversion of testosterone to oestrone or oestradiol was detected.