In vitro metabolism of androstenedione and identification of endogenous steroids in Helix aspersa

In vitro metabolism of androstenedione in gonads of juvenile and adult Helix aspersa has been investigated. The conversion of [ 3H]androstenedione into testosterone, 5α-dihydrotestosterone, androsterone, and estriol was demonstrated. In juvenile animals testosterone (59.8%) is the major metabolite whereas in adult animals androsterone (18.8%) is. The following endogenous steroids have been identified by gas chromatography—mass spectrometry in adult gonads: androsterone, dehydroepiandrosterone, androstenedione, 3α-androstanediol, estrone, estradiol-17β, and estriol. The levels of testosterone, 5α-dihydrotestosterone, androstenedione, and progesterone have been measured by RIAs in gonads and hemolymph. Their levels vary with the physiological stage: the gonadal and circulating levels of testosterone decrease with the sexual maturation whereas the 5α-dihydrotestosterone increases. These differences observed in metabolism and in level of steroids between the juvenile and the adult snails allow us to suppose that these steroids have a biological role.