C19-radiosteroid disposition in organ cultures of transplanted prostatic adenocarcinomas of the Noble rat.

This study compares the disposition of 8.5-nM C19-radiosteroids in 21-h cultures of Noble rat dorsolateral prostate (DLP) and transplanted adenocarcinomas derived from the DLP. Our purpose was to determine whether differences in androgen activation could be detected between the androgen-stimulated tumor (AST) line, an androgen-independent tumor line carried in intact (AIT-I) and castrated (AIT-C) rats and their DLP tissue of origin. No differences were found between DLP, AST, AIT-I, and AIT-C for the following parameters: 5 alpha-reduction of [3H]testosterone to dihydrotestosterone (DHT); however, conversion to total 5 alpha-reduced metabolites was lower in AIT-C than DLP cultures; explant retention of [3H]testosterone-derived DHT; tissue capacity to hydroxylate [3H]5 alpha-androstane-3 beta,17 beta-diol; total and nuclear high-affinity binding of [3H]DHT to salt-extractable explant protein, except for one AIT-C which yielded half the number of binding sites. Since AIT carried in either intact or castrated hosts is competent as regards formation, retention and high-affinity binding of [3H]DHT in organ culture, we conclude that the neoplasm possesses some of the characteristics considered essential for the expression of androgen responsiveness in vivo.