Regulation of the beta 2-adrenergic receptor and its mRNA in the rat ventral prostate by testosterone.

To investigate the regulation of beta 2AR expression in rat ventral prostate the effects of castration and testosterone replacement on the beta 2AR were studied by ligand binding and Northern blot analysis. Orchidectomy depressed beta 2AR number by 50% within 4 days and testosterone administration to 4-day castrates produced a rapid and complete recovery of beta 2AR number within 24 h. In contrast to receptor number, beta 2AR mRNA levels did not change relative to total RNA following castration. However, during the testosterone replacement period beta 2AR mRNA levels rose transiently, reaching a maximum (3.5-fold) between 8 and 12 h, and this increase in mRNA preceded the recovery in beta 2AR number in the membrane. Regulation of beta 2AR gene expression by testosterone in the ventral prostate is thus complex and probably involves both transcriptional and post-transcriptional components.