In vitro conversion of 5alpha-reduced metabolites of testosterone by the seminal vesicles, ventral prostate glands and testes of adult rats

Efficacy of various natural and synthetic androgens to induce ductal branching morphogenesis in the developing anterior rat prostate

The studies presented herein quantitated ductal branching morphogenesis in the anterior prostate (AP) of the newborn rat. Four parameters were measured: epithelial area, epithelial perimeter, node number, and form factor. Nine natural and synthetic androgens were tested for their effectiveness in inducing postnatal prostatic development using 808 newborn rat APs in 68 dose-response experiments. Based on these studies it was shown that testosterone (T) was slightly more effective than dihydrotestosterone (DHT) in supporting ductal branching morphogenesis in the developing rat AP. Furthermore, the activity of T could not be accounted for simply by conversion of T to DHT. Synthetic androgens, 7alpha-methyl-19-nortestosterone and methyltrienolone (R1881), which cannot be 5alpha-reduced to DHT, also induced extensive ductal branching and elicited responses less than those to T and not statistically different from those to DHT. This suggests that although DHT is sufficient for prostatic development, it is not necessary for postnatal ductal branching morphogenesis and growth of the prostate. 5Alpha-androstan-3alpha,17beta-diol was particularly potent in inducing ductal branching, eliciting a response greater than or comparable to those of T and DHT. Androsterone, androstanedione, 5alpha-androstan-3beta,17beta-diol and 5beta-androstan-3alpha,17beta-diol induced ductal branching, but to a lesser extent than either T or DHT. These studies challenge the assumption that DHT is essential for prostatic development, specifically during ductal branching morphogenesis of the neonatal rat prostate.

Seasonal variations of androgens, estrogens, and progesterone in the different lobules of the testis and in the plasma of Salamandra salamandra

Progesterone, 4-androstenedione, testosterone, dihydrotestosterone, 5 alpha-androstane-3 alpha,17 beta-diol (3 alpha-diol), 5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol), estrone, and estradiol levels were determined by radioimmunoassay in the different lobules of the testis of Salamandra salamandra throughout the year according to the seasonal cycle. 3 beta-diol levels were not detectable. High levels of steroids were found in the grandular tissue (enlarged pericystic cells after spermiation) and large variations were showed for progesterone, 4-androstenedione, testosterone, 3 alpha-diol, and estrone. In the mature lobule (formed by cysts with mature spermatozoa), only testosterone showed seasonal variations and in the immature lobule (with early stages of meiosis), 3 alpha-diol showed fluctuations. The major estrogen found in the testis of Salamandra was estrone; estradiol stayed at a low level throughout the cycle. The steroids fluctuation seems to be related to the histological evolution of the testis throughout the cycle. The present data were the first on steroid seasonal variations in the testis of an urodele.

The synthesis of 3H labelled steroid-nitrogen mustard derivatives and studies on their action in rat and human prostate

Tissue receptor proteins are thought to be a key factor in selective retention and nuclear translocation of steroid hormones in their target tissues. Steroid-cytotoxic derivatives with high affinity for these receptor proteins may, therefore, be useful as site directed agents in the treatment of hormone dependent cancers. The prostatic retention and subcellular localisation of estramustine and a 17 beta nitrogen mustard derivative of 5 alpha-dihydrotestosterone have been compared since the latter compound has higher androgen receptor binding affinity than the former. The 5 alpha-dihydrotestosterone derivative was not retained more avidly than estramustine by either human or rat ventral prostatic tissue. Nuclear localisation could not be detected with either compound. The cytotoxic action of these compounds requires the liberation of the nitrogen mustard moiety. The cleavage rate of both compounds was low but similar in both benign and malignant prostatic tissues. We conclude that steroids are unlikely to be suitable agents for directing cytotoxic compounds to prostatic tissue particularly if the steroid-cytotoxic derivative requires metabolism for the expression of the cytotoxic activity.

The role of androgen metabolism in the control of androgen action in the rat prostate

Recent results from a number of laboratories have led us to re-examine the role of 3 beta-androstanediol in the rat ventral prostate. Whereas previously 5 alpha-dihydrotestosterone and 3-beta androstanediol were thought to have distinctly separate effects on the prostate, we suggest that 3 beta-androstanediol serves only as an intermediate in the metabolism and removal of 5 alpha-dihydrotestosterone from the organ. In our view the action of androgens on the prostate are exerted exclusively through the binding of 5 alpha-dihydrotestosterone to the androgen receptor and its subsequent translocation to the nucleus. Differences in effects are related to the amount of 5 alpha-dihydrotestosterone available to the gland. 3 alpha-Hydroxysteroid dehydrogenase may play a critical role in modulating the level of 5 alpha-dihydrotestosterone available to the translocatable receptor.

Synthesis and androgen effects of 7 alpha,17 beta-dihydroxy-5 alpha-androstan-3-one, 5 alpha-androstan-3 alpha,7 alpha,17 beta-triol and 5 alpha-androstane-3 beta,7 alpha,17 beta-triol

The steroids 7 alpha,17 beta-dihydroxy-5 alpha-androstan-3-one (7 alpha-hydroxy-Dht), 5 alpha-androstan-3 alpha,7 alpha,17 beta-triol (7 alpha-hydroxy-3 alpha-A'DIOL) and 5 alpha-androstane-3 beta,7 alpha,17 beta-triol (7 alpha-hydroxy-3 beta-A'DIOL) have been synthetized from 7 alpha,17 beta-dihydroxy-4-androsten-3-one (7 alpha-hydroxy-testosterone). The effect of administering 7 alpha-hydroxy-Dht, 7 alpha-hydroxy-3 alpha-A'DIOL or 7 alpha-hydroxy-3 beta-A'DIOL on serum levels of LH, FSH and on ventral prostate and seminal vesicle weight were investigated in gonadectomized adult male rats. Each steroid was administered for seven days in a dose of 300 micrograms per day. No suppression of serum LH or FSH levels was recorded following injections of these 7 alpha-hydroxylated steroids to castrated rats, compared to castrated control rats receiving vehicle only. Administration of 7 alpha-hydroxy-Dht or 7 alpha-hydroxy-3 alpha-A'DIOL to castrated mature rats could maintain ventral prostate and seminal vesicle weights above that of castrated control rats. Administration of 7 alpha-hydroxy-3 beta-A'DIOL to castrated mature rats resulted in ventral prostate weights slightly above castrate control levels, while seminal vesicle weight in such rats were in the same range as castrated control rats. Intraperitoneal administration of testosterone or of 5 alpha-androstane-3 beta,17 beta-diol (3 beta-A'DIOL) to castrated rats maintained activity of the androgen dependent isoenzyme of acid phosphatase in the ventral prostate; 7 alpha-hydroxy-testosterone or 7 alpha-hydroxy-3 beta-A'DIOL showed, however, no effect on this enzymic activity.

Metabolism of 5 alpha-androstane-3 beta,17 beta-diol to 17 beta-hydroxy-5 alpha-androstan-3-one and 5 alpha-androstan-3 alpha,17 beta-diol in the rat

Significant metabolism of 5 alpha-androstane-3 beta,17 beta-diol to 17 beta-hydroxy-5 alpha-androstan-3-one was recorded in several tissues and organs from rats and humans. This bioconversion was further investigated in rat testis homogenates. 5 alpha-Androstane-3 beta,17 beta-diol was readily metabolized to 17 beta-hydroxy-5 alpha-androstan-3-one with NAD and/or NADP added as cofactors. When a NADPH generating system was included in the incubation, 5 alpha-androstane-3 beta,17 beta-diol was metabolized to 5 alpha-androstan-3 alpha,17 beta-diol. Only small amounts of 17 beta-hydroxy-5 alpha-androstan-3-one accumulated under the latter condition.

The effects of 5alpha-reduced androgens on maintenance and regeneration of prostate glands and seminal vesicles in castrated and hypophysectomized rats

The effects of 5alpha-androstane-3alpha, 17beta-diol (3alpha-diol) and 5alpha-androstane-3beta, 17beta-diol (3beta-diol) were studied in rats hypophysectomized and treated daily for 30 days with the steroids, starting on the day of surgery (hypophysectomized, H) or 30 days following the removal of pituitary (hypophysectomized regressed, HR). The ability of 3beta-diol to maintain and restimulate the prostate glands and seminal vesicles of castrated (C) and castrated regressed (CR) rats, respectively, was also studied. This androgen (3beta-diol) was able to maintain as well as rejuvenate to some degree the sexual accessory glands of all treatment groups. The prostate glands and seminal vesicles in both castrated experimental groups showed increased stimulation with progressively higher dosages of 3beta-diol. At all dose levels, stimulation of seminal vesicles of CR rats was comparable to that of non-regressed castrates. The prostate glands, on the other hand, showed better maintenance in the higher dosage group. In H rats, the stimulation of sexual accessory glands by both androgens was not significantly different than normal controls. The seminal vesicles and prostate glands of HR rats treated with 3alpha-diol were well stimulated and comparable to those of H rats treated with 3alpha-diol. The seminal vesicles of HR rats treated with 3beta-diol were also well stimulated, though not to the extent as those with 3alpha-diol treatment. The prostate glands of the 3beta-diol treated HR rats were significantly smaller than those of the 3alpha-diol treatment group. However, these miniature glands were morphologically stimulated as evidenced by mitosis of parenchymal cells and accumulation of secretory products in the alveoli. This study clearly indicates that 3beta-diol is biologically active and the degree of stimulation varies with the animal preparation in which the androgens were tested.