Steroid biosynthesis in vitro by the component tissues of the ovary of dogfish (Scyliorhinus caniculus L.)

SUMMARY Ovaries of dogfish were separated into their component tissues and incubated separately with [4-14C]dehydroepiandrosterone and androstenedione. Production of Δ4-3-oxosteroids from the former was localized in the follicular membrane, in the post-ovulatory corpora lutea and in the egg yolk. Reduction of androstenedione to testosterone was higher in corpora lutea than in corpora atretica and higher in follicular membranes and yolks taken from ripe follicles than in those taken from atretic eggs. Production of oestradiol-17β from androstenedione was limited to the follicular membranes of ripe follicles and to the ovarian stroma; oestrone production was demonstrated, additionally, in corpora atretica and their membranes. There was no indication of oestriol formation.