3\g=a\-HYDROXYSTEROIDDEHYDROGENATION IN SUBCELLULAR FRACTIONS OF RAT VENTRAL PROSTATE AND OTHER TISSUES

Dehydrogenation of androsterone, catalysed by both particulate and soluble fractions of rat ventral prostate, has been demonstrated in vitro by spectrophotometric and chromatographic methods. A difference has been observed between dehydrogenases in the particulate and soluble fractions in their acceptance, under uniform experimental conditions, of the 5\g=a\and 5\g=b\isomers, androsterone and aetiocholanolone, as substrate. The parti-culate enzyme dehydrogenates androsterone under conditions in which aetiocholanolone is not dehydrogenated, whereas the soluble enzyme utilizes equally androsterone and aetiocholanolone as substrate. An examination of other rat tissues by the chromatographic method has confirmed the wide-spread occurrence of the soluble dehydrogenase. Particulate dehydrogenase resembling the prostatic enzyme was detected in seminal vesicle and kidney