Journal of steroid biochemistry vol:17 issue:3 pages:319-30
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.