Development of dimethandrolone 17beta-undecanoate (DMAU) as an oral male hormonal contraceptive: induction of infertility and recovery of fertility in adult male rabbits.

Dimethandrolone undecanoate (DMAU: 7α,11β-dimethyl-19-nortestosterone 17β-undecanoate) is a potent orally active androgen with progestational activity that is in development for therapeutic uses in men. We hypothesized that because of its dual activity, DMAU might have potential as a single-agent oral hormonal contraceptive. To test this possibility, adult male rabbits (5/group) of proven fertility were treated orally with vehicle or DMAU at 1.

Long-term effects of dimethandrolone 17β-undecanoate and 11β-methyl-19-nortestosterone 17β-dodecylcarbonate on body composition, bone mineral density, serum gonadotropins, and androgenic/anabolic activity in castrated male rats.

The potent androgens dimethandrolone 17β-undecanoate (DMAU) and 11β-methyl-19-nortestosterone 17β-dodecylcarbonate (11β-MNTDC) are in development for androgen replacement therapy and hormonal contraception in men. They can be delivered either orally or as long-acting injectables. In the current study, their long-term effects on body composition (percentage lean and fat mass); bone mineral density (BMD); serum gonadotropin levels; and weights of the prostate, seminal vesicles, and levator ani muscle were assessed.

The potent synthetic androgens, dimethandrolone (7α,11β-dimethyl-19-nortestosterone) and 11β-methyl-19-nortestosterone, do not require 5α-reduction to exert their maximal androgenic effects.

Dimethandrolone (DMA: 7α,11β-dimethyl-19-nortestosterone) and 11β-methyl-19-nortestosterone (MNT) are potent androgens in development for hormonal therapy in men. As 5α-reduced androgens, such as 5α-dihydrotestosterone (DHT), may raise the risk of benign prostate hyperplasia, accelerate the development of prostate carcinoma, and increase male pattern baldness and acne, we investigated the role of 5α-reduction in the androgenic activity of DMA and MNT. The authentic 5α-reduced metabolites, 5α-dihydroDMA (5α-DHDMA) and 5α-dihydroMNT (5α-DHMNT), were prepared by chemical synthesis and compared in vitro and in vivo to the parent compounds.

Relative progestational and androgenic activity of four progestins used for male hormonal contraception assessed in vitro in relation to their ability to suppress LH secretion in the castrate male rat.

Male hormonal contraceptive regimens are generally combinations of an androgen and a progestin which suppress gonadotropin secretion and, consequently, spermatogenesis. The activities of four synthetic progestins, levonorgestrel (LNG), norethindrone acetate (NETA), cyproterone acetate (CPA), and nestorone (NES), used in combination with testosterone for male hormonal contraception were compared in vitro and in vivo. In vitro assays (steroid hormone receptor binding and transactivation) focused on their relative androgenic vs progestational potencies.

Effects of synthetic androgens on liver function using the rabbit as a model.

The objective of this study was to determine whether the rabbit was a suitable model to test new synthetic androgens for potential liver toxicity within a short dosing interval. Adult male rabbits were dosed orally daily on days 0-13 with 17α-methyltestosterone (MT) as a positive control and testosterone (T) as a negative control to validate this model. Synthetic androgens tested were: 7α-methyl-19-nortestosterone (MENT), dimethandrolone-undecanoate (DMAU), and 11β-methyl-19-nortestosterone-17β-dodecylcarbonate (11β-MNTDC).

Mechanism of action of bolandiol (19-nortestosterone-3beta,17beta-diol), a unique anabolic steroid with androgenic, estrogenic, and progestational activities.

Bolandiol is a synthetic anabolic steroid that increases lean body mass and bone mineral density without significant stimulation of sex accessory glands in castrate adult male rats. Since bolandiol suppresses gonadotropins and endogenous testosterone (T) production, we investigated its mechanism of action. We compared the potency of bolandiol in vitro and in vivo with T, 5alpha-dihydrotestosterone (DHT), 19-nortestosterone (19-NT) and estradiol (E(2)).

Dimethandrolone (7alpha,11beta-dimethyl-19-nortestosterone) and 11beta-methyl-19-nortestosterone are not converted to aromatic A-ring products in the presence of recombinant human aromatase.

Dimethandrolone undecanoate (DMAU: 7alpha,11beta-dimethyl-19-nortestosterone 17beta-undecanoate) is a potent orally active androgen in development for hormonal therapy in men. Cleavage of the 17beta-ester bond by esterases in vivo leads to liberation of the biologically active androgen, dimethandrolone (DMA), a 19-norandrogen. For hormone replacement in men, administration of C19 androgens such as testosterone (T) may lead to elevations in circulating levels of estrogens due to aromatization.

A novel potent indazole carboxylic acid derivative blocks spermatogenesis and is contraceptive in rats after a single oral dose.

Women have historically been the focus for development of new contraceptive methods. The National Institutes of Health, World Health Organization, and Institute of Medicine have stressed the need to develop nonhormonal, nonsteroidal male contraceptive agents. We report results from initial dose-ranging studies of a new indazole carboxylic acid analogue, gamendazole.

Mechanism of action of l-CDB-4022, a potential nonhormonal male contraceptive, in the seminiferous epithelium of the rat testis.

The present study was conducted to elucidate the possible molecular mechanisms involved in the antispermatogenic activity of l-CDB-4022, an indenopyridine. In this study 45-d-old male Sprague-Dawley rats were treated with a single oral dose of l-CDB-4022 (2.5 mg/kg) or vehicle, and blood and testes were collected at various time points.

Comparison of progesterone and glucocorticoid receptor binding and stimulation of gene expression by progesterone, 17-alpha hydroxyprogesterone caproate, and related progestins.

Objective: This study was undertaken to determine whether the reduction in premature birth attributable to 17-alpha hydroxyprogesterone caproate occurs because of a greater affinity for progesterone or glucocorticoid receptors or by enhanced stimulation of progestogen responsive genes when compared with progesterone.

Study Design: We performed competitive steroid hormone receptor binding assays using cytosols expressing either recombinant human progesterone receptor-A or -B or rabbit uterine or thymic cytosols. We used 4 different carcinoma cell lines to assess transactivation of reporter genes or induction of alkaline phosphatase.

Facilitation or inhibition of the oestradiol-induced gonadotrophin surge in the immature female rat by progesterone: effects on pituitary responsiveness to gonadotrophin-releasing hormone (GnRH), GnRH self-priming and pituitary mRNAs for the progesterone receptor A and B isoforms.

Progesterone can either facilitate or inhibit the oestradiol (E(2))-induced gonadotrophin surge. We have previously developed immature female rat models to characterise and investigate the mechanisms of progesterone inhibition or facilitation. The aim of the present study was to determine the role of pituitary responsiveness to gonadotrophin-releasing hormone (GnRH) and GnRH self-priming under conditions of progesterone-facilitation and progesterone-inhibition, and whether the underlying mechanisms reflect changes in mRNAs encoding the A and B isoforms of the progesterone receptor (PR) in the pituitary gland.

Development of l-CDB-4022 as a nonsteroidal male oral contraceptive: induction and recovery from severe oligospermia in the adult male cynomolgus monkey (Macaca fascicularis).

The present study was undertaken to examine the antispermatogenic effect of l-CDB-4022 in the adult male cynomolgus monkey. Monkeys (four per group) were dosed via nasogastric tube for 7 d with l-CDB-4022 at 12.5 mg/kg.

Glucocorticoid repression of the reproductive axis: effects on GnRH and gonadotropin subunit mRNA levels.

Activation of the stress axis by glucocorticoids suppresses reproductive function in many species. Here, we performed studies to determine whether these effects are mediated at the level of the hypothalamus or pituitary or both, and to dissect the underlying molecular mechanisms, using two established rodent models. Rats were treated either chronically or acutely with glucocorticoids, and circulating gonadotropins, GnRH mRNA levels, and gonadotropin subunit mRNAs levels were measured.

Dimethandrolone undecanoate: a new potent orally active androgen with progestational activity.

Dimethandrolone (DMA), the 17beta-undecanoic acid ester of dimethandrolone (DMAU; 7alpha,11beta-dimethyl-19-nortestosterone) is a potent androgen currently in development for therapeutic uses in men. Cleavage of the 17beta-ester bond liberates the biologically active DMA. In this study we investigated the activity of DMAU and DMA both in vivo and in vitro.

Steroid hormonal regulation of growth, prostate specific antigen secretion, and transcription mediated by the mutated androgen receptor in CWR22Rv1 human prostate carcinoma cells.

CWR22Rv1 (22Rv1) is an androgen-responsive human prostate carcinoma cell line derived from a primary prostate tumor that expresses mutant (H874Y) androgen receptors (AR) and secretes low levels of prostate specific antigen (PSA). In this study, we examined the effects of various androgens and other steroid hormones on proliferation of 22Rv1 cells, PSA secretion, and transactivation. Incubation of 22Rv1 cells with various concentrations of testosterone resulted in a dose-dependent 50-80% increase in growth over 72 h.

In vitro antiprogestational/antiglucocorticoid activity and progestin and glucocorticoid receptor binding of the putative metabolites and synthetic derivatives of CDB-2914, CDB-4124, and mifepristone.

In determining the biological profiles of various antiprogestins, it is important to assess the hormonal and antihormonal activity, selectivity, and potency of their proximal metabolites. The early metabolism of mifepristone is characterized by rapid demethylation and hydroxylation. Similar initial metabolic pathways have been proposed for CDB-2914 (CDB: Contraceptive Development Branch of NICHD) and CDB-4124, and their putative metabolites have been synthesized.

The ability of a gonadotropin-releasing hormone antagonist, acyline, to prevent irreversible infertility induced by the indenopyridine, CDB-4022, in adult male rats: the role of testosterone.

Intratesticular testosterone (ITT) is known to play a critical role in the maintenance of spermatogenesis. We have used acyline, a GnRH antagonist, to suppress testosterone (T) production, and acyline and T implants to study the prevention of irreversible infertility induced by CDB-4022. Vehicle or acyline was administered to proven fertile male rats (n = 5/group) at a dose (210 microg/day) that completely suppressed (P < 0.

CDB-4124 and its putative monodemethylated metabolite, CDB-4453, are potent antiprogestins with reduced antiglucocorticoid activity: in vitro comparison to mifepristone and CDB-2914.

To obtain selective antiprogestins, we have examined the in vitro antiprogestational/antiglucocorticoid properties of two novel compounds, CDB-4124 and the putative monodemethylated metabolite, CDB-4453, in transcription and receptor binding assays and compared them to CDB-2914 and mifepristone. All four antiprogestins bound with high affinity to rabbit uterine progestin receptors (PR) and recombinant human PR-A and PR-B (rhPR-A, rhPR-B) and were potent inhibitors of R5020-induced transactivation of the PRE2-tk-luciferase (PRE2-tk-LUC) reporter plasmid and endogenous alkaline phosphatase production in T47D-CO human breast cancer cells. None of these compounds exhibited agonist activity in these cells.

Modulation of IL-18 production in the adrenal cortex following acute ACTH or chronic corticosterone treatment.

Interleukin (IL)-18 is a proinflammatory cytokine and a stimulator of cell-mediated immune responses. We have previously reported that acute stress stimulates the production of IL-18 mRNA in the glucocorticoid (GC)-producing cells of the adrenal cortex. In order to investigate the mechanisms governing the expression of IL-18 in the adrenal cortex, the effects of acute ACTH or chronic corticosterone treatment on the levels of IL-18 mRNA and protein were examined by in situ hybridization and Northern and Western blot assays.

Transcriptional regulation of the glycoprotein hormone alpha-subunit gene by pituitary adenylate cyclase-activating polypeptide (PACAP) in alphaT3-1 cells.

We showed previously that pituitary adenylate cyclase-activating polypeptide (PACAP) increases glycoprotein hormone alpha-subunit gene expression and secretion in alphaT3-1 cells. We have now used 5'-flanking deletion and clustered point mutations of the mouse alpha-subunit promoter fused to the luciferase (LUC) reporter gene in transient transfection assays to further characterize the cell signaling pathways and sequences involved in responsiveness to PACAP. PACAP stimulated LUC activity at a lower concentration than VIP, supporting the notion that PACAP acts through type 1 receptors.

Mathematical exploration of pulsatility in cultured gonadotropin-releasing hormone neurons.

Pulsatile gonadotropin-releasing hormone (GnRH) release has been demonstrated in cultures of an immortalized line of GnRH expressing neurons (GT1 cells) in experiments by four different research groups. Pulsatile release is known to play a crucial role in GnRH-mediated signaling in vivo, and thus deserves theoretical and quantitative consideration, especially as GT1 cells are presumably genetically homogeneous. Here we have modeled idealized GT1 cells with a differential equation/logic based modeling program, Stella II.

Progesterone blockade of a luteinizing hormone surge blocks luteinizing hormone-releasing hormone Fos activation and activation of its preoptic area afferents.

Progesterone is capable of facilitating or blocking the luteinizing hormone (LH) surge, depending on the timing of its administration. However, the precise targets of progesterone's actions are unknown. Since recent studies described the presence of a periventricular preoptic area (pePOA) neuron population afferent to LH-releasing hormone (LHRH) neurons that is co-activated to express c-Fos with LHRH neurons at the time of the LH surge, the present study was designed to determine if the pePOA neurons contain progesterone receptors (PRs) and whether progesterone inhibition is manifested by a failure of LHRH and pePOA neurons to become activated at the time of an LH surge.

Glucocorticoid repression of gonadotropin-releasing hormone gene expression and secretion in morphologically distinct subpopulations of GT1-7 cells.

Two morphologically distinct subpopulations of GT1-7 cells have been characterized and examined for their responsiveness to glucocorticoids. Type I cells have a neuronal phenotype, extending many lengthy processes, and express neuronal, but not glial, markers. Type II cells show weaker or negative immunostaining for neuronal markers and exhibit fewer processes.

Facilitation or inhibition of the estradiol-induced gonadotropin surge in the immature rat by progesterone: regulation of GnRH and LH messenger RNAs and activation of GnRH neurons.

Unlabelled: We have developed and extensively characterized immature female rat models to demonstrate inhibition or facilitation of the estradiol (E2)-induced gonadotropin surge by progesterone (P). We show here that the surge of free alpha-subunit is regulated similarly by P in these models. To investigate the possibility that P alters the biosynthesis of GnRH and/or LH, we measured levels of LH subunit mRNAs by Northern blot hybridization and GnRH mRNA by a solution hybridization-RNase protection assay.