Changes in the cytoplasmic androgen receptor of rat ventral prostate after administration of androgens, antiandrogens and anabolic steroids.

The effect of the administration of androgens (testosterone and dihydrotestosterone(, antiandrogens (progesterone and cyproterone acetate) and anabolic steroids (Bolandiol, Nandrolone, Furazabol and Methenolone) on depletion and replenishment of the androgen receptor in the cytosol of ventral prostate from castrated rats was examined using 3H-R1881 as the ligand. Administration of androgens lead to a rapid fall in the level of the receptor and the receptor in the cytosol was replenished in the period following treatment. Length of the period of receptor depletion was dependent on the dose of androgen administered. Administration of antiandrogens did not cause any depletion of the receptor and concomitant administration of testosterone induced a pattern similar to that of the depletion observed following administration of testosterone alone. Effect of pretreatment of animals with ethidium bromide, an intercalating dye which has been shown to prevent the in vitro nuclear binding of steroid hormone-receptor complexes, on the depletion of receptor induced by testosterone administration was also insignificant. Anabolic steroids depleted the receptor but the degree of depletion was relatively low. The rate of inhibition of in vitro 3H-R1881 binding by these anabolic steroids was not correlated to the rate of in vivo depletion of the receptor. The significance of these observations is discussed.