Androgen and progestogen production in cultured interstitial cells derived from immature rat testis

Interstitial cells derived from intact immature rats were cultured as monolayers. Their response to gonadotropins was evaluated by radioimmunoassay of 3',5'-cyclic AMP and steroids in the medium. Steroids were measured either directly (testosterone and progesterone) or after previous oxidation and thin layer chromatographic purification of the steroid extracts (4-androstene-3,17-dione, 5 alpha-androstane-3,17-dione, progesterone, 5 alpha-pregnane-3,20-dione). It could be demonstrated that these cells respond to gonadotropins with increased secretion of C19- and C21-steroids for at least 10 days. The total amount of steroids secreted in the medium, however, decreases markedly. During the first days of culture C19-steroid production falls dramatically whereas the secretion of C21 derivatives increases. A major fraction of the extracted steroids has undergone 5 alpha-reduction. A characteristic feature of cultured interstitial cells is the bell-shaped profile of the dose-response curve for gonadotropin stimulated androgen production. This profile is the result of a steroidogenic lesion situated at the level of the 17 alpha-hydroxylase and/or 17,20-desmolase and induced by high concentrations of gonadotropins. Daily changes with medium supplemented with LH or FSH, initiated on day 3 of culture, prevent a further loss of steroidogenic potential, restore the ability to produce C19-derivatives, and tend to normalize the dose-response curve for gonadotropin stimulated production of androgens.