In vitro biosynthesis of steroids, including 11-deoxycortisol and 5α-pregnane-3β,7α,17,20β-tetrol, by ovaries of the goldfish Carassius auratus during the stage of oocyte final maturation

Abstract

To examine the production of steroids with potential oocyte maturation-inducing or pheromonal activity in the goldfish ( Carassius auratus) we have incubated mature ovaries of this species with 17-[ 3H]hydroxyprogesterone. The metabolites in the unconjugated, glucuronide, and sulfate fractions were identified by chromatography, microchemical reaction, and, in most cases, crystallization to constant specific activity. A major metabolite, present in all three fractions, was tentatively identified as 5α-pregnane-3β,7α,17,20β-tetrol. Although 17,20β-dihydroxy-4-pregnen-3-one (17,20β-P) was found in only low yield (as a sulfate), the presence of the tetrol indicates that it is synthesized in high yield but very rapidly metabolized. The relative proportions of 17,20α-dihydroxy-4-pregnen-3-one (17,20α-P), 11-deoxycortisol (17,21-dihydroxy-4-pregnen-3,20-dione) and 17,20β,21-trihydroxy-4-pregnen-3-one (17,20β,21-P) varied significantly between incubations and may be affected by the maturational state of the ovary or the method used to stimulate oocyte maturation. Testosterone was present predominantly as its glucuronide. Significant production of glucuronides and sulfates was observed in all incubations. Twenty-five to 30% of the radioactivity remained associated with the tissue, but the distribution of activity between the metabolites did not differ greatly from that found in the medium. These results indicate that 11-deoxycorisol and its 20β-reduced derivative (17,20β,21-P) may be significant in spawning female goldfish.