Morphofunctional study of the effects of fetal exposure to cyproterone acetate on the hypothalamo-pituitary-gonadal axis of adult rats.

Fetal exposure to cyproterone acetate (CPA), while allowing, normal sexual morphogenesis, has previously been shown to lead to functional endocrine abnormalities in adult rats of both sexes. Because of this, we examined morphologically and morphometrically the hypothalamic nuclei involved in sexual dimorphism as well as the pituitary lactotropes of rats exposed in utero from day 15 to 20 of gestation to CPA. Male and female offspring was studied at the age of 70-80 days. In both sexes the brain weight was lower (p less than 0.05) in CPA-treated than in control rats. Morphometrical investigations showed that the surface density (Sv) and the volume density (Vv) of the ventromedial nucleus were higher (p less than 0.05) in CPA-treated male than in control rats. By comparing sexes the Sv and Vv of the ventromedial nucleus were higher (p less than 0.01) in CPA-treated male than in corresponding female rats. Also the nuclear surface of the tyrosine hydroxylase-immunoreactive neurons of the arcuate nucleus was higher (p less than 0.05) in CPA-treated male than in female rats. In lactotropes of the pituitary gland the immunoreactive prolactin (PRL) was densitometrically increased (p less than 0.05) in CPA-treated female compared with control rats. By electron microscopy, PRL granules and autophagocytosis appeared to be more abundant in CPA-treated rats of both sexes. These data show that fetal exposure to CPA results in long-term anatomical and physiological alterations of hypothalamic and preoptic nuclei as well as of the pituitary lactotropes. These permanent changes support the functional endocrine abnormalities observed in adult rats.

Effect of steroid hormones and antihormones on hypothalamic beta-endorphin concentrations in intact and castrated female rats.

The aim of the present study was to evaluate the effects of estrogens and androgens on hypothalamic beta-endorphin (beta-EP) concentrations. Intact or castrated female rats were chronically (2 weeks) treated with estrogen (estradiol benzoate) and/or antiestrogens (clomiphene, cyclophenil or epimestrol), and with androgens (dihydrotestosterone or dehydroepiandrosterone sulphate) and/or antiandrogen (cyproterone acetate). A group of rats treated with vehicle were studied as comparison. The beta-EP concentrations were measured by radioimmunoassay on acidic extracts of rat hypothalami. The administration of clomiphene and cyclophenil significantly reduced hypothalamic beta-EP concentrations in intact rats, while both drugs or estradiol benzoate increased the peptide concentration in castrated rats. Both intact and castrated rats treated with epimestrol showed hypothalamic beta-EP concentrations higher than vehicle treated rats. The estradiol-induced increase of beta-EP was not changed by the concomitant administration of antiestrogens. The administration of dihydrotestosterone significantly decreased beta-EP concentrations in both intact and castrated female rats, while the treatment with dehydroepiandrosterone sulphate only slightly decreased beta-EP levels in intact female rats. The cyproterone acetate-chronically treated rats showed higher beta-EP concentrations than vehicle-treated rats and these changes were reversed by the concomitant addition of dihydrotestosterone or dehydroepiandrosterone sulphate. These results showed that estrogens play a positive role while androgens negatively influence the hypothalamic beta-EP concentrations in female rats, supporting the view that central beta-EP might be a target of gonadal steroid feedback signals.

Biopotency and site of action of drugs affecting testicular steroidogenesis.

The effect of etomidate (an anaesthetic), epostane (WIN 32729; an inhibitor of ovarian and adrenal steroidogenesis) and cyproterone acetate (an antiandrogen) on testosterone secretion from mouse Leydig cells stimulated with LH (5 i.u./l) was tested. The concentration of drug which inhibited testosterone secretion by 50% was 11.5 +/- 1.1 (S.E.M.) mumol/l for cyproterone acetate, 1.2 +/- 0.2 mumol/l for etomidate and 0.23 +/- 0.03 mumol/l for epostane. The effect of all three drugs on testicular steroidogenesis was completely reversible. Thus testicular cells which had been washed after exposure to a greater than 95% inhibitory dose of drug responded in a similar manner to hormone stimulation as cells similarly washed and which had not been exposed to the drug. The sites of the antisteroidogenic effect of epostane, etomidate and cyproterone acetate were established using a method based on the sequential stimulation by the exogenous precursor steroids of the various steps leading to the biosynthesis of testosterone. It was concluded that etomidate acts at the sequence between LH binding and pregnenolone production, epostane acts at 3 beta-hydroxysteroid dehydrogenase and cyproterone acetate inhibits 3 beta-hydroxysteroid dehydrogenase and C17,20-lyase.

Inhibition of testosterone metabolism in the brain and cloacal gland of the quail by specific inhibitors and antihormones.

The effects of antioestrogens, antiandrogens and of various inhibitors of testosterone metabolism on testosterone metabolism in the quail hypothalamus and cloacal gland were studied by an in-vitro radioenzymatic assay. It was found that antioestrogens and antiandrogens generally had little or no effect on aromatase and 5 alpha- and 5 beta-reductases of testosterone, except when used at very high doses. The 5 alpha-reductase inhibitor, 17 beta-N,N-diethylcarbamoyl-4-methyl-4-aza-5 alpha-androstan-3-one, inhibited both 5 alpha- and 5 beta-dihydrotestosterone production without markedly affecting aromatase activity. Surprisingly, the aromatase inhibitor, 1,4,6-androstatriene-3,17-dione, inhibited not only the production of oestradiol but also that of 5 beta-dihydrotestosterone and, to a lesser extent, 5 alpha-dihydrotestosterone. These unexpected properties should be taken into account when interpreting the results of in-vivo experiments using these compounds.

Effect of antiandrogens on the hypothalamic gamma-aminobutyric acid (GABA) and glutamate contents of the Indian palm squirrel (Funambulus pennanti, Wroughton).

Intramuscular administration of 20 mg/kg flutamide (Flut) or 50 mg/kg of cyproterone acetate (CPA) daily for a period of three weeks significantly elevated the hypothalamic GABA content. CPA is found to decrease the hypothalamic glutamate level while Flut elevated it. Both, Flut and CPA reduced the hypothalamic weight.

Action of drugs and chemical agents on rat liver regeneration.

Chemical agents and drugs of widely differing pharmacological activity have been administered to partially hepatectomized male rats and the extent of liver regeneration ascertained over a period of 10 days. Of the large number investigated, the following fed ad lib in diets supplemented in a basal ration at the weight percentages indicated, proved to be hepatotrophic: anticonvulsants - mephenytoin (0.15), methsuximide (0.15), phensuximide (0.15) and primidone (0.10); benzodiazepines - clobazam (0.10), flurazepam hydrochloride (0.12), halazepam (0.070), oxazepam (0.030) and temazepam (0.10); anti-inflammatory agents - benoxaprofen (0.040), ibuprofen (0.10 and 0.20), naproxen (0.040) and sulindac (0.075); sedatives and hypnotics - ethinamate (0.75), glutethimide (0.075), methaqualone (0.030 and 0.10) and methprylon (0.30) and the analgesic and antipyretic, aminopyrine (0.15); antifungal - griseofulvin (0.50); anti-androgen - cyproterone acetate (0.020 and 0.050); uricosuric - sulfinpyrazone (0.050 and 0.20); skeletal muscle relaxant - chlorzoxazone (0.20); hydrocholeretic - florantyrone (0.30); anti-hypertensive - prazosin hydrochloride (0.010) and the thyroid inhibitor, methimazole (0.025). The feeding of several of the stimulants at the given levels to intact males elicited wet and dry liver enlargement. Most of the current test agents as screened in operated rats, had little effect on the regeneration and in fact, tended to depress the process when higher levels were fed or injected.

[Regulation and determinants of sex behavior]. / Regulation und Prägung des Sexualverhaltens.

One has to distinguish masculine sex behavior and estrogens alone or in combination with gestagens evoke feminine sex behavior. The central integrator for the induction of sex behavior is located in diencephalic nuclei. If sex hormones are lacking, the sex drive is fading off, except in women. Sex hormones are also responsible for the determination of those neutral centres controlling male or female sex behavior later in life in most species. Based on animal datas and on retrospective inquiries of homosexuals or mothers of homosexuals, a hypothesis for the etiology of homo-, bi- and hyposexuality has been developed by Dorner. Absence or deficiency of androgens in the critical phase of "brain differentiation" leads to male homo-, bi- or hyposexuality, respectively. If androgens become active in the critical phase of female differentiation, then the result will be female homo-, bi- or hyposexuality, respectively. This hypothesis will be critical evaluated.

Progestogens with antimineralocorticoid activity.

The ability of 11 steroids with varying degrees of progestogenic potency to inhibit the renal actions of aldosterone was tested in adrenalectomized, glucocorticoid-treated rats. The rats were continuously infused with an isotonic solution of low sodium content (0.05% NaCl + 5.2% glucose, 3 ml/rat/h) supplemented with d-aldosterone [1 microgram/(kg X h)] resulting in a long-lasting reduction in renal sodium excretion, increase in renal potassium excretion and hence decrease in the urinary Na/K-ratio. The test drugs were administered either subcutaneously or orally 1 h before start of infusion. Their antimineralocorticoid activity was judged by the increase in the aldosterone-lowered Na/K-ratio in urine which was collected at hourly intervals for 15 or 21 h, respectively. Adrenalectomized, glucocorticoid-treated rats receiving an i.v. infusion without aldosterone were used for assessing possible mineralocorticoid effects of the steroids tested. D-Norgestrel, norethisterone acetate, 3-keto-desogestrel (the active metabolite of desogestrel) and cyproterone acetate, respectively, did neither show antimineralocorticoid nor mineralocorticoid activity when injected subcutaneously at a dose of 53.3 mg/kg. In contrast, gestodene (26.7 or 53.3 mg/kg s.c., respectively), progesterone (53.3 mg/kg s.c.), spironolactone (26.7 mg/kg s.c.), spirorenone (13.3 mg/kg s.c.), 1,2-dihydro-spirorenone (13.3 mg/kg s.c.), or 1,2 alpha-methylene-spirorenone (13.3 mg/kg s.c.) exhibited significant anti-mineralocorticoid activity. Canrenone (53.3 mg/kg s.c.) slightly increased the urinary Na/K-ratio. This effect, however, was not significant. Gestodene, like spironolactone or progesterone, was devoid of aldosterone-like mineralocorticoid activity. With the exception of progesterone, the antimineralocorticoid activity of the steroids tested could also be demonstrated after oral administration. Based on the Na/K-ratio or the log (Na X 100)/K-ratio, the potency of each test compound relative to spironolactone was evaluated using regression analysis. The following results (average relative potency, spironolactone = 1.0) were obtained: gestodene: approximately 0.2; canrenone: approximately 0.3-0.35; spirorenone: approximately 7-8; 1,2-dihydro-spirorenone: approximately 8; 1,2 alpha-methylene-spirorenone: approximately 3.5. Progesterone which was evaluated after s.c. injection exhibited an average relative potency of approximately 0.35. Due to these results, gestodene may be regarded as the first progestogen of the nortestosterone series exhibiting a more natural, progesterone-like profile of activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Antiandrogenic effects of cyproterone acetate and chloromadinone acetate on the rat hypothalamus as revealed by electroencephalographic responses.

Bipolar stainless steel electrodes were implanted stereotaxically into given hypothalamic and cortical regions of the brain of 48 rats. The animals were divided into two groups of equal numbers and the electrical activity of the given regions was recorded electroencephalographically (EEG). The effect of the acute and chronic administration of cyproterone acetate (CPA) or chloromadinone acetate (CHA), in doses inducing sterility, on EEG activity were observed. Apart from slight inhibition in the preoptic region, no appreciable EEG changes were found after CPA, while CHA reduced the discharge frequency in both the preoptic and the posterior hypothalamus. These findings can be attributed to the presence of two different types of androgen receptors in the hypothalamus.

Value of xenografts in the investigation of prostatic function: preliminary communication.

Two of 33 prostatic tumour xenografts were established and passaged. Testosterone supplementation did not improve tumour take rates. The histological grade of the parent tumour was the principal factor affecting xenograft survival. Preliminary studies on established tumour xenografts suggest that their value lies in the study of tumour biology, and that they have no direct therapeutic application at present.

Proliferation of lamellar whorls in arcuate neurons of the hypothalamus of male rats treated with estradiol benzoate or cyproterone acetate.

The arcuate nucleus of the hypothalamus (AH) of male rats which had been treated either with estradiol benzoate (E2B) or cyproterone acetate (CPA) was examined ultrastructurally for the presence of whorls of endoplasmic reticulum. The incidence of whorl containing neurons (WCN) was 2-4 times higher in the AH of animals treated for 2-3 weeks with E2B or for 2 weeks with CPA than in the AH of oil treated controls. CPA is a powerful anti-androgen while E2B acts both peripherally and centrally to limit testosterone production. These findings, together with previous evidence that whorls proliferate in AH of male rats deprived of androgen by morphine treatment or castration, suggest that steroid feedback (androgen alone or both androgen and estrogen) plays an important role in AH whorl preliferation. The possibility that WCN may be LH-RH containing neurons is suggested by the close correspondence between the number and location of WCN within AH as determined in this study and the distribution of LH-RH containing cells reported by others.

Some new approaches to potential test systems for drugs against prostatic cancer.

We have previously reported on test systems, based on 5alpha-reductase (5alpha-RA) and arginase activities and steroid deposition in animal prostates, potentially useful in screening drugs possibly effective in cancer of the prostate. Recently, we have concentrated on the development of other in vivo and in vitro systems which may prove of further value in testing such drugs. These systems include the following: (a) The effects of drugs on 5alpha-RA activity in human and animal non-malignant and human cancerous prostatic tissues in organ culture. The parameters necessary for the maintenance of optimal 5alpha-RA in such explants have been determined, and it has been shown that certain agents (estramustine phosphate, progesterone, estradiol-17beta) can inhibit 5alpha-RA under in vitro conditions, pointing to the potential use of such an approach in screening various cytostatic agents. In addition, 65Zn deposition, the histology, and the androgen metabolism in such tissues in organ culture are being determined as additional parameters. (b) The deposition of 65Zn in the rat dorsolateral gland, particularly as affected by prolactin and testosterone, and the effects of chemotherapeutic agents on such deposition. Methotrexate and CCNU have been shown to be potent inhibitors of 65Zn deposition in the dorsolateral gland. The parameters related to zinc metabolism in the prostate are being further investigated. (c) The demonstration of receptors for estrogens (estradiol-17beta, diethylstilbestrol) in the prostate of the baboon. The various parameters related to the specificity of such receptors have been established. The development and standardization of these approaches, some facets of which are reported in the present publication, may prove them to be more sensitive, specific, and optimal than other systems and should afford an opportunity to test various combinations of drugs potentially useful in cancer of the prostate with relative speed, efficacy, and ease of manipulation.

[Testosterone-7alpha-3H uptake by the anlage of organs related to reproduction in female rate embryos in experiments in vivo and in vitro]. / Pogloshchenie testosterona-7alpha-3H zakladkami organov, sviazannykh s reproduktsiei, u zarodyshei-samok krys v opytakh in vivo i in vitro.

The dynamics of testosterone-7alpha-3H (T-3H) uptake by the developing genital system organs, as well as by the suprarenals, brain cortex and muscles was studied in vivo experiments with the 14-20 days old female rat embryos. Besides, the T3H uptake by the reproductive tract tissues and muscles just after the isolation of embryos from the uterus and after 2 days cultivation in the diffusion chambers implanted in the abdominal cavity of the adult castrated rats was studied in in vitro experiments. Moreover, the T3H uptake by the embryonic tissues was determined in the absence of ovaries. The specific uptake was noted in all the tissues at all developmental stages under all experimental conditions. The selective T3H uptake was noted during the periods corresponding to the rudiments' morphogenesis carachteristic for males. In the absence of ovaries, the T3H uptake by the reproductive tract tissues in vitro experiments decreased, but after 2 days cultivation in the diffusion chambers increased. The possible participation of ovaries in the female sex differentiation and the bisexual nature of rudiments determined by the presence of receptors both to estro- and androgens are discussed.

Regional and subcellular [3h]estradiol localization in selected brain regions and pituitary of female mice: effects of unlabeled estradiol and various anti-hormones.

Groups of ovariectomized mice were pretreated for 30 min with either vehicle, unlabeled estradiol benzoate or one of the following anti-hormones: cyproterone acetate, CI-628 or CN-69, 725-27. One hour after an I.V. injection of [3H]estradiol the levels of toluence extractable radioactivity retained in the crude nuclear and cytosol fractions of selected brain regions, pituitary and plasma were determined by liquid scintillation spectrometry. The major findings were: (1) In vehicle treated animals [3H]estradiol uptake in the pituitary greatly exceeded that in all brain regions. Within the brain uptake was greatest in the preoptic anterior hypothalamus (POA-AH) and medial basal hypothalamus (MBH) samples. Nuclear uptake exceeded cytosol uptake only in the pituitary and POA-AH and MBH samples. (2) Estradiol benzoate pretreatment greatly reduced nuclear, and to a lesser extent cytosol [3H]estradiol uptake in pituitary, POA-AH and MBH samples. Estradiol benzoate pretreatment also reduced nuclear uptake in the dorsal middle hypothalamus (DMH). (3) The anti-androgen cyproterone acetate, previously shown to have anti-estrogenic effects in female sexual behavior tests, was found to have no effect on nuclear or cytosol [3H]estradiol uptake in brain and pituitary. (4) The anti-estrogen CI-628 was found to reduce nuclear [3H]estradiol uptake in the POA-AH and pituitary samples. It also reduced cytosol [3H]estradiol uptake in the pituitary sample. The anti-estrogen CN-69, 725-27 produced a much greater inhibition of nuclear [3H]estradiol uptake than CI-628 in the POA-AH, MBH, DMH, dorsal posterior hypothalamus and pituitary samples. This anti-estrogen also reduced cytosol [3H]estradiol uptake in the POA-AH, MBH and pituitary samples. (5) A preliminary chromatographic analysis of vehicle control samples indicated that 70-98% of the nuclear radioactivity in target regions such as POA-AH, MBH and pituitary was iso-polar with authentic estradiol, while less than 50% of the radioactivity in plasma and cortex behaved as estradiol.