Metiamide potentiates the stimulant actions of sympathomimetic amines "in vitro"

Metiamide significantly potentiated the contractions of the guinea-pig and the rat vas deferens and seminal vesicle produced by noradrenaline, dopamine and methoxamine. The responses to acetylcholine and carbachol were not affected by metiamide. Tetrodotoxin did not affect metiamide-induced potentiation of the sympathomimetics. Potentiation induced by metiamide was Ca++-dependent. Mepyramine failed to influence the responses to the amines. It is suggested thaat extra-neuronal mechanisms may be involved in the interactions of metiamide and sympathomimetics.

Effect of aminoglutethimide on androgenic functions in mice

Administration of aminoglutethimide (EliptenR, CIBA) to intact and castrated male mice decreased the weight of seminal vesicles and kidneys of intact males. However, the effect was not additive to that of orchietomy. Testicular cholesterol and protein content was significantly increased by aminoglutethimide, whereas no significant changes in testicular weight and blood testosterone were found, both being only moderately decreased.

Control of reabsorption of water and electrolytes by guinea-pig seminal vesicle in vivo

Guinea-pig seminal vesicles reabsorbed Na+ and K+ in vivo from a standard bicarbonate buffer against both electrical and chemical gradients. Water was reabsorbed with the ions. Concentrations of Na+ and K+ in the reabsorbate were greater than in plasma or the initial buffer perfusate. Guinea-pigs castrated for 6 days did not reabsorb water or electrolytes, but daily administration of testosterone or 5 alpha-dihydrotestosterone restored normal reabsorption rates. Addition of prostaglandin E-2 to the perfusate inhibited water and Na+ reabsorption. Section of the hypogastric nerve did not affect reabsorption rates measured 10 days later. We suggest that the guinea-pig seminal vesicle maintains a basal reabsorptive capacity to remove electrolytes and water that diffuse or are secreted into the lumen and that the reabsorptive pump may be coupled to a secretory one activated intermittently and perhaps partly modulated by prostaglandins.

Augmentation of luteinizing hormone action by prostaglandin E2 in the prevention of antispermatogenic effect of indomethacin. Indomethacin & spermatogenesis

Administration of indomethacin exhibited antigonadal action by inhibiting the Leydig cells, sex-accessories and spermatocyte-spermatid conversion process. Administration of PGE2 or PGF2 alpha had no effect on Leydig cell nuclear volume or accessory organ weights, but PGE2 had a restorative effect on the efficiency of meiosis, although at a statistical non-significant level. Administration of LH to indomethacin treated rats restored the accessories fully with a non-significant effect on the yield of step-7 spermatids from meiosis. Simultaneous administration of indomethacin, LH and PGE2 (but not PGF2 alpha) restored both sex-accessories and spermatid number to the level of vehicle injected controls.

Cyproterone acetate and seminal vesicles in the regulation of male fertility

The effect of continuous release of microquantities of cyproterone acetate from subcutaneously implanted silastic capsules on the fertility of surgically manipulated seminal vesicles of rat has been studied. The experimental animals showed infertility for 3 weeks, as a consequence of removal of seminal plasma, following which normal fertility returns as efficiently as that operated control. However, a significant decrease in weight of the testes and epididymides, were recorded. It appears that seminal vesicles can synthesize seminal plasma even at very low levels of androgen in the presence of cyproterone acetate.

An interaction between the pineal gland and olfactory deprivation in potentiating the effects of melatonin on gonads, accessory sex organs, and prolactin in male rats

Male rats (25-26 days of age) housed with 14 hours of light per day (lights on 0600--2000 hours) were either olfactory bulbectomized (rendering them anosmic), bulbectomized plus pinealectomized (Pinx), or left intact. On the day following the operations, intact, anosmic, and anosmic-Pinx animals began receiving single, daily afternoon (1700--1800 hours) subcutaneous injections of 50 microgram of melatonin (MEL) for six weeks, while an additional group of intact controls received injections of diluent. At the end of this period, body, anterior pituitary, testicular, and seminal vesicle weights were significantly reduced in intact-MEL-treated animals. Anosmic animals that had been treated with MEL experienced a further, highly significant, 65%, 90%, and 85% depression in testicular, seminal vesicle, and ventral prostate weights, respectively, as compared with intact control and MEL-treated rats. Additionally, both body and anterior pituitary weights were significantly decreased in MEL-treated, anosmic rats. Anosmic-Pinx rats treated with MEL had organ and body weights that were intermediate between those of intact-MEL and anosmic-MEL-treated animals. Pituitary and serum levels of prolactin (Prl) were significantly lower in anosmic-MEL-treated rats than in intact-MEL-treated groups. Similarly, Prl levels were depressed in the anosmic-Pinx rats treated with MEL; however, serum Prl was not statistically lower than in intact or intact-MEL-treated animals. These results indicate that anosmic male rats have an increased sensitivity to antigonadotrophic and Prl-inhibitory effects of MEL. Futhermore, the data suggest that the presence of the pineal gland in anosmic rats is important in permitting anosmia maximally to sensitize the neuroendocrine-reproductive axis to the antigonadotrophic effects of exogenously administered MEL.

Sex steroids imprinting and prostatic growth

Sex steroids exposure to rats castrated at birth during the neonatal or prepubertal period permanently modified certain morphologic features of the accessory sex organs in adulthood. Similar treatment of intact rats failed to induce these changes. Hypophysectomy in adulthood did not abolish the neonatally androgen-induced imprinting of the growth response of the rat accessory sex organs in adulthood, which suggests that the effects of neonatal androgen administration are directly on the hormone-responsive target cells and are not mediated via the hypothalamic-pituitary axis.

Contractile capacity of seminal vesicles from rats in different hormonal conditions

Isometric contractions of seminal vesicles excised from normal, castrated, estradiol-, testosterone- or norandrostenolone - treated castrated rats were recorded in order to compare their contractile capacity. When expressed as grams of tension per strip of muscle, the vesicles of the castrated rats exhibited the smallest contractile capacity. The contractile force of the organs taken from estradiol-treated castrated rats was higher than that shown by the vesicles of castrates but smaller than those taken from normal, testosterone- or norandrostenolone- treated-castrates. There was no correlation between the contractile force and previously reported reactivity of seminal vesicles.

Basic antiinflammatory compounds. N,N',N''-Trisubstituted guanidines

A variety of basic N,N',N'',-trisubstituted guanidines was prepared and tested for antiinflammatory activity. Compounds with a thiazolylguanidine moiety linked to the 4 position of the 2-methylquinoline ring exhibited fairly high antiinflammatory activity. Optimal activity was associated with the presence of N-cycloalkyl substituents on N''-4-(2-methylquinolyl)-N'-2-thiazolylguanidine. Pharmacological data on N-cyclohexyl-N''-4-(2-methylquinolyl)-N'-2-thiazolylguanidine (SR 1368, 44) are presented and discussed.

Androgenic regulation of messenger RNA sequence complexity in accessory sexual tissues of the male rat studied with fractionated complementary DNA

Effects of androgens on mRNA sequence complexity in the rat seminal vesicle have been investigated using complementary DNA fractionated on the basis of sequence abundance. Total cDNA complementary to poly(A)-rich RNA from normal rats was hybridised with an excess of the same RNA to controlled rot values and then the free cDNA was separated from cDNA . RNA hybrids by hydroxyapatite chromatography. Three cDNA fractions were obtained with very different hybridisation characteristics. Abundant cDNA hybridised to an excess of its parental RNA with an rot 1/2 of 2.46 x 10(-3) mol 1(-1) s and is complementary to about six or seven average-sized sequences. Use of hybrid-arrested translation in a cell-free protein-synthesising system has shown that this class of mRNA includes mRNAs coding for major androgen-dependent secretory proteins. Moderate and scarce cDNA fractions each showed more complex hybridization kinetics; computer analysis suggested each is complementary to two groups of average-sized sequences. Each cDNA fraction was hybridised to excess poly(A)-rich RNA from normal or castrated rats and the kinetics compared. Castration had no effect on the total number of sequences present in any class and did not alter the relative concentration of the scarce sequences. A small (threefold) decrease was seen in the concentration of abundant sequences with a larger (tenfold) decrease in the moderate class. Both de-reases were reversed by testosterone in vivo. The results are consistent with earlier studies where the effects of testosterone on seminal vesicle mRNA were followed using a translation assay and confirm that no gross differential effects are exerted on abundant mRNA coding for major secretory proteins. The cDNA fractions were also used to investigate the overlap in genetic expression between seminal vesicle and ventral prostate. Both tissues share all the scarce sequences in the same relative abundance. Less than 0.0015% and 0.004% of prostatic mRNA is complementary to seminal vesicle abundant and moderate sequences respectively. Similarly prostatic abundant sequences account for less than 0.004% of seminal vesicle mRNA.

Anti-androgen TSAA-291. III. Hormonal spectra of anti-androgen TSAA-291 (16 beta-ethyl-17 beta-hydroxy-4-oestren-3-one) and its derivatives

For the purpose of obtaining hormonal spectra of anti-androgen TSAA-291 and its derivatives, a variety of endocrine characteristics were studied. (1) Androgenic and anabolic activity : Subcutaneous administration of anti-androgen TSAA-291 and its acetate, TSAA-328, to the immature orchiectomized rat resulted in significant weight increase of the levator ani but in only a nominal response of seminal vesicles and prostates even at a large daily dose of 9.6 mg. The resultant anabolic/androgenic ratio was estimated to be extremely high. (2) Oestrogenic activity : Uterine weight in response to these anti-androgens were sluggishly dose-dependent, and the maximal plateau response remained considerably lower than that induced by oestradiol-17 beta. The oestrogenic activity of these anti-androgens was estimated to be 1/200 000 or less as that of oestradiol-17 beta. A single subcutaneous dose of 100 mg of TSAA-291 or its caproate, TSAA-330, did not induce the vaginal cornification in the adult ovariectomized rat. (3) Anti-oestrogenic activity : Antagonistic effect of these anti-androgenic compounds on the uterine weight response to oestradiol-17 beta was found in the immature ovariectomized rat. A single subcutaneous dose of 100 mg of TSAA-291 or TSAA-330 also induced the antagonism against the cornification caused by daily treatments with 1 microgram oestrone in the adult ovariectomized rat. (4) Progestational activity : These anti-androgenic compounds proved to be less active than progesterone in the McPhail's test. (5) Anti-inflammatory activity : Daily subcutaneous dose of 20 mg of TSAA-291 for 6 days did not significantly depress the weight of granuloma developed around the cotton-pellet implanted in the young male rat. TSAA-291 did not affect the anti-inflammatory action of 1/6 mg of prednisolone phosphate. Combination of both agents seemed to be effective in enhancing the anti-androgenic action of TSAA-291, whereas prednisolone phosphate alone rather increased the weight of the accessory sex organs. (6) Liver glycogen deposition activity : Daily intramuscular doses up to 38.4 mg of TSAA-291 for 5 days did not increase the liver glycogen level in the adrenalectomized rat.

Anti-androgen TSAA-291. II. Manifestation of the anti-androgenic action of a steroid ester TSAA-330 (16 beta-ethyl-17 beta-hydroxy-4-oestren-3-one caproate) and elucidation of its long-lasting mechanism using a simple steroid determination technique

Using a simple steroid determination technique, in situ steroid absorption from a subcutaneously injected sesame oil solution in rats was pursued following the time-course changes in the steroid concentration. Based on the knowledge thus obtained, the anti-androgenic effect of a steroidal compound, TSAA-330, could be manifested in the subcutaneous route. (1) Anti-androgenic steroid TSAA-291 and its esters in the subcutaneously injected sesame oil solution were selectively absorbed into the general circulation at different rates according to their chemical nature and structures, while the oil itself remained at the injected site for a considerably long period. At the injected site where subcutaneous doses of steroids molar equivalent to 50 mg of TSAA-291 were administered in 5 ml/rat of sesame oil, TSAA-291 decreased to the level of 10% of the initial concentration on the 4th day. TSAA-328 decreased slowly to the 50% and 20% levels on the 7th and 21st day, respectively. TSAA-335 decreased more slowly to the 50% level on the 14th day. TSAA-330 decreased most slowly only to the 70% level on the 49th day. (2) A single subcutaneous administration of 200 mg of TSAA-330 suppressed the weight increase of the accessory sex organs caused by a single subcutaneous injection of testosterone caproate (10 mg) in the immature orchiectomized rat. The suppressive effect was obvious from 2 weeks after the administration, and seemed to last for more than two weeks. The levator ani weight was not affected by the administration of TSAA-330. (3) Dose-dependent inhibitions of the accessory sex organs were obtained three weeks after a single subcutaneous administration of 50 to 400 mg of TSAA-330 in the adult male rat. (4) Daily oral administrations of 50 mg of TSAA-291 or TSAA-330 to the adult male rat for 8 days resulted in depression of the accessory sex organs to almost the same extent obtained with either agent. One week after the last administration, however, the weight of the accessory sex organs of the TSAA-291-administered animals recovered to almost the comparable level with the control, whereas a significant after-effect of the inhibition was still evident in the TSAA-330-administered animals.

Time-studies of the changes in the sex-dependent activities of enzymes of hepatic steroid metabolism in the rat during oestrogen administration

This investigation was undertaken to elucidate the amount of oestradiol and duration of its administration necessary to cause complete feminization of the activities of cytoplasmic 3 alpha- and 17 beta-hydroxysteroid dehydrogenase, microsomal 3 alpha- and 3 beta-hydroxysteroid dehydrogenase and microsomal 5 alpha-reductase in male rat liver. With the exception of cytoplasmic 3 alpha-hydroxysteroid dehydrogenase, 5 microgram oestradiol/d for 8 days and less was sufficient to cause complete feminization. The order of oestrogen sensitivity was cytoplasmic 3 alpha-hydroxysteroid dehydrogenase greater than microsomal 3 beta-hydroxysteroid dehydrogenase greater than microsomal 3 alpha-hydroxysteroid dehydrogenase greater than microsomal 5 alpha-reductase greater than cytoplasmic 17 beta-hydroxysteroid dehydrogenase. Although the changes occurring after oestradiol administration are qualitatively the same as after testectomy, they occur more rapidly. This rules out the possibility that oestradiol exerts its effect via androgen deprivation. Diethylstilboestrol administration causes the same changes in cytoplasmic 17 beta- and microsomal 3 beta-hydroxysteroid dehydrogenase activity as oestradiol, although the dosage must be increased 100 fold. The effect of diethylstilboestrol on 5 alpha-reductase activity changes with the dose applied. Doses up to 100 microgram/d partially feminize the activity, but at higher doses the enzyme activity is repressed.

Chronic effects of [D-Trp6,Pro9-NEt]luteinizing hormone-releasing factor on reproductive processes in the male rat

Chronic administration of a potent LRF agonist, [D-Trp6,Pro9-NEt]LFR (A), to intact adult male rats induced a dose-related decrease in testicular and accessory organ weights, diminished production of testosterone (T), and disrupted tubular morphology, indicative of suppression of spermatogenesis. Transient elevations of plasma progesterone levels and a marked reduction of PRL secretion were also observed in A-treated rats. The effects of A on testicular weights, T levels, and seminiferous tubule morphology were already apparent 3 days after the first injection. Administration of A was equally effective when administered daily or at 1- to 4-day intervals in lowering steroid levels and testicular weights. After a 1-week daily exposure to A, seminal vesicles and prostate weights as well as T levels returned to control values within 1--2 weeks. Testicular weights, however, were still depressed 4 weeks after cessation of treatment, and germinal epithelium was disrupted in 30--40% of the tubules. Measurement of T and LH plasma levels after each daily injection of A indicated a blunting of succeeding A-induced elevations of LH and T, which lasted up to 72 h after a single administration of A. The observation that cultured pituitary cells repeatedly exposed to A showed a similar blunting of LRF-induced LH elevation suggests that the decrease in pituitary responsiveness was not exclusively due to steroid feedback. Administration of T propionate to A-treated intact rats was unable to restore normal testicular weights and seminiferous tubule morphology, whereas in hypophysectomized rats, T propionate maintained qualitatively normal spermatogenesis even in the presence of A. These results coupled with the observation that high levels of hCG and PMS gonadotropin had effects similar to those of A on the tubular morphology of intact rats suggest the importance of pituitary secretion in mediating the deleterious effects of A on reproductive functions in the male rat.

Action of exogenously administered steroid hormones following perinatal exposure to polybrominated biphenyls

Polybrominated biphenyls (PBBs) have produced a variety of effects including alterations in the endocrine system and in the activity of microsomal mixed-function oxidases (MFOs). Because steroid hormones are substrates for MFOs, effects of PBBs on the endocrine system may be a consequence of enhanced steroid hormone catabolism. Therefore, as a first step in evaluating the effect of PBBs on steroid hormone catabolism. Therefore, as a first step in evaluating the effect of PBBs on steroid hormone metabolism, it was of interest to determine effects of perinatal exposure to PBBs on the response to exogenously adminstered steroid hormones. Rats were exposed to 0, 10, or 100 ppm PBBs from d 8 of gestation until d 28 postpartum, when experiments were conducted. Responses to labeled steroid hormones were generally modified in a manner directly related to PBB dose and were correlated with changes in serum and target tissue retroactivity. Stimulated metabolism of steroid hormones may account, at least in part, for endocrine-related alterations produced by PBBs. Although the potential for decreased reproductive capacity following PBBs cannot yet be accurately predicted, these experiments suggest that fertility may be reduced following PBBs as a consequence of accelerated steroid hormone metabolism and/or excretion.

[Doses levorin display an antiandrogenic action?]

The antiandrogenic effect of levorin on immature castrated rats treated with exogenic testosterone was studied. In a dose of 200 mg/kg levorin lowered the cholesterin blood levels in the rats, inhibited the testosterone-induced increase in RNA concentration in the ventral and dorsal prostate and the seminal vesicles and to a less extent suppressed the growth of the accessory sexual glands. However, the antiandrogenic effect was observed with the use of levorin in the dose producing a pronounced toxic action evident from death of a part of the animals and a marked decrease in the animal body weight. This fact casts doubt on specificity of the levorin effect. Apparently, in high doses levorin impairs metabolism as a whole which cannot but affect the response of the sexual glands to administration of testosterone.