Androgenic Control of Polysomal Poly(A)-containing RNA in the Cultured Rat Ventral Prostate

Testosterone stimulated, at the concentration of 10-7 M and independently of other hormones, the accumulation of polysomal poly(A)-containing RNA (mRNA) in cultured explants of rat ventral prostate and concomitantly also protein synthesis. The hormone-induced accumulation of polysomal mRNA, which reached its maximum at 24 h after testosterone addition, paralleled the preferential labeling of high molecular weight RNA demonstrable with the electrophoretic analysis of the double-isotope labeled RNA after a short pulse (30 min). These findings are consistent with the idea that testosterone activated the synthesis of precursor mRNA leading to an increased amount of polysomal mRNA and eventually an activated protein synthesis. The synthesis and maturation of rRNA appeared to proceed even in the absence of testosterone, which is in contrast to the vivo findings on castrated rats. This partial uncoupling of RNA synthesis from androgenic control may account for the slow and less marked hormonal responses found in protein synthesis and glucose metabolism in cultured explants from normal animals. Because of the lack of uniformity in the suture, routine light microscopic control to assess the viability of cultured explants was found to be a prerequisite for successful biochemical work on prostate culture.