THE ROLE OF TESTOSTERONE AND ANDROSTENEDIONE AS PRECURSORS OF EPITESTOSTERONE IN GUINEA PIGS (IN VIVO AND IN VITRO STUDIES)

ABSTRACT After injection of [7α- 3 H] androstenedione and [4- 14 C] testosterone into male and female guinea pigs, doubly labelled aetiocholanolone, 5α-androstanedione and epi androsterone were identified in the urine. No epi testosterone was detected. Ovaries, testes, adrenals and liver slices were incubated with the same precursors. Epi testosterone production was observed in all organs except in the adrenals. According to the epi testosterone 3 H/ 14 C ratio, it can be concluded that in guinea pigs an interconversion of testosterone, androstenedione and epi testosterone takes place. In liver, androstenedione is preferentially converted to epi testosterone without sex differences, whereas in ovary and testis epi testosterone derives preferentially from testosterone.