Effects of testosterone buciclate on testicular and epididymal sperm functions in bonnet monkeys (Macaca radiata)

In vitro assessment of reproductive toxicity on rats induced by organic contaminants of source water

The safety of drinking water attracts more and more attention these years. This study focused on the reproductive toxicity of source water in Jiangsu Province, China. The organic contaminants of source water are capable of bioaccumulating and cause health effects on human beings. The toxicological tests on Spermatogenic cells, Sertoli cells and Leydig cells of male rats showed that source water extracts can reduce testicular cells membrane integrity and depress cell viability significantly. Among these testicular cells, Leydig cells are most sensitive to organic contaminants and the testosterone secretion of Leydig cells is evidently disturbed correspondingly. The phenols in the source water may be chiefly responsible for the reproductive toxicity. These data indicated that chronic reproductive toxicity of source water cannot be overlooked and action should be taken to protect human health from the threat of organic pollution of source water.

The reproductive toxicity of organic compounds extracted from drinking water sources on Sprague Dawley rats: an in vitro study

The safety of drinking water always causes worldwide concern. Water pollution increases with urban development and industrialization in developing countries. During recent decades, increasing numbers of environmental organic compounds have been found in aquatic environments. These organic compounds are capable of bioaccumulating to much higher concentrations in food webs and cause health effects on human beings. Reproductive impairment is one of the commonest consequences of environmental pollution. Our goal was to investigate the reproductive toxicity of organic compounds extracted from surface water samples collected in drinking water sources. This study focused on the surface water in lower Yangtze River and Taihu Lake, which act as drinking water sources of Jiangsu province, one of the most rapidly developing regions in China. We used solid-phase extraction (SPE) to condense organic compounds by 286 times from natural surface water samples and established in vitro system to evaluate their effects on reproductive system. We found that organic compounds destroyed the plasma membrane integrity of Sertoli cells and Spermatogenic cells to a certain degree and significantly depressed viability of Sertoli cells and Spermatogenic cells as well. Accordingly, the proportion of apoptotic Sertoli cells and dead Spermatogenic cells enhanced markedly. Although viability of organic-compound-treated Leydig cells did not come down remarkably, testosterone production of Leydig cells decreased evidently. These results suggest that accumulated comprehensive effects of organic compounds in surface water of drinking water sources may induce spermatogenesis malfunction and reduction of testosterone production in the long term.

Effects of levonorgestrel butanoate alone and in combination with testosterone buciclate on spermatogenesis in the bonnet monkey

The spermatogenic effects of levonorgestrel butanoate were studied in adult male bonnet monkeys when administered alone and in combination with testosterone buciclate. Levonorgestrel butanoate (0.25, 1.0 and 2.5 mg kg(-1)) given as two injections on days 0 and 60 (groups II, III, IV) resulted in thickening and folding of the basement membrane and disruption of cell associations in groups III and IV (on day 120). In group II, no apparent changes in testicular histology were observed. When these doses of levonorgestrel butanoate were combined with 40 mg of testosterone buciclate (groups V, VI, VII), maximum changes were seen in group VI in which all stages of spermatogenesis were absent on day 120 except for a small number of spermatogonia. The changes caused by lower dose (group V) and higher dose (group VII) of levonorgestrel butanoate were less prominent than in group VI. A significant decrease in the number of dark A (Ad) and B spermatogonia was observed in all groups except for Ad spermatogonia on day 120 in group V, B spermatogonia on day 60 in group IV and B spermatogonia on day 120 in group III. A significant decrease in pachytene spermatocytes was seen on day 120 in groups V only. Early spermatids showed a significant decrease only in groups V and VII on day 120 of treatment. Advanced spermatids were suppressed significantly in group IV on day 60 and in groups IV and V on day 120. These data indicate that levonorgestrel butanoate (1.0 mg kg(-1)) in combination with 40 mg of testosterone buciclate was the most effective treatment in suppressing spermatogenesis. The site of action of this combination regimen is at the level of renewing Ad spermatogonia.

Pharmacological developments in male contraception

To date, the current methods of male contraception are limited to condoms, coitus interruptus and vasectomy, all of which are beset with difficulties. The condom is inconvenient, dulls sensation, and although somewhat effective against sexually transmitted disease, has an increased failure rate over time of usage. Coitus interruptus reduces the pleasurable aspects of intercourse and is plagued with a high failure rate. Vasectomy is virtually sterilisation. The current research into new forms of contraception is as diverse as the mechanisms controlling male fertility. The majority of effort has focused on antispermatogenic agents. Hormonal agents that suppress spermatogenesis appear nearest to final development and are primarily centred around various testosterone esters. These can be administered alone or in combination with progestogens. Another promising line of study centres on gonadotropin releasing hormone (GnRH) antagonism resulting in suppression of gonadotropins. Non-hormonal antispermatogenic agents include numerous phytochemicals, and testicular enzyme inhibitors. Post-testicular approaches to male contraception include agents that interfere with sperm metabolism, motility, maturation or transport. This review summarises recent clinical and animal studies on these compounds with emphasis on their mechanism of action, advantages and drawbacks.

Pharmacokinetics and degree of aromatization rather than total dose of different preparations determine the effects of testosterone: a nonhuman primate study in Macaca fascicularis

Currently available testosterone (T) preparations differ substantially in their pharmacokinetic profile that might influence their androgenic properties in terms of suppression of the gonadal axis, effects on anabolic parameters, lipid metabolism, and erythropoiesis. The present work was undertaken to determine the physiological effects of three T preparations with different serum kinetics. Twenty adult male cynomolgus monkeys (Macaca fascicularis) were randomly assigned to receive treatment for 28 weeks with either T enanthate (TE) every 4 weeks, T buciclate (TB) every 7 weeks, or T undecanoate (TU) every 10 weeks or remaining untreated (controls). Each injection delivered 20 mg pure T per kilogram body weight. Pharmacokinetic profiles demonstrated higher peak levels of T for TE-treated animals; serum half-lives were longer for TU or TB. Estradiol levels (area under the curve) were significantly higher in TB vs TU or TE. All T regimens suppressed serum luteinizing hormone bioactivity and testicular volumes declined (all P <.001 vs controls). Sperm counts were markedly lowered in all animals but least in TE (P <.01 vs TB or TU). During recovery phase, return to normal for all three parameters occurred significantly earlier in TE-treated animals, followed by those given TU, compared with TB (all P <.001 between groups). Body weight increased significantly during T exposure. This effect was stronger and more sustained in TB vs TU or TE (both P <.001). Serum creatinine and hemoglobin increased with high significance in all T-treated animals (all P <.001 vs controls). The lowering impact of T on serum lipids was markedly stronger in the longer-acting T preparations in comparison with TE, as were effects on purine metabolism (all P <.001). The pattern of exposure and degree of aromatization rather than overall exposure to T determine its effects in the preclinical primate model. Both fluctuations of androgen concentrations and the conversion rate to estradiol influence gonadal suppression as well as metabolism. These results have to be considered in men receiving treatment for hypogonadism or regimens for hormonal contraception.

Current status of fertility control methods in India

Approximately 48.2% of couples of 15 to 49 years of age practice family planning methods in India. Female sterilization accounts for 34.2%, with male sterilization declining from 3.4% in 1992-93 to 1.9% in 1998-99. Use of the condom increased to 3.1% from 2.4%. There is an urgent need for research to develop new contraceptive modalities especially for men and also for women and to make existing methods more safe, affordable and acceptable. Current efforts in India to develop a male contraceptive are mainly directed towards (i) development of antispermatogenic agents to suppress sperm production, (ii) prevention of sperm maturation, (iii) prevention of sperm transport through vas deferens or rendering these sperm infertile and (iv) prevention of sperm deposition. Research work in the field of prevention of sperm transport through vas deferens has made significant advances. Styrene maleic anhydride (SMA) disturbed the electrical charge of spermatozoa leading to acrosome rupture and consequent loss in fertilizing ability of sperm. A multicentre phase-III clinical trial using SMA is continuing and it is hoped that the SMA approach would be available in the near future as an indigenously developed injectable intra-vasal male contraceptive. The safety and efficacy of available oral contraceptives were evaluated. An indigenously developed oral contraceptive 'Centchorman', which is a nonsteroidal, weakly estrogenic but potently antiestrogenic, was found to be safe and effective and is now being marketed in India since 1991 as a 'once a week' pill. Cyclofem and Mesigyna have been recommended as injectable contraceptives with proper counselling and service delivery by Indian studies. It has been recommended that these injectable contraceptives be added to the existing range of contraceptive methods available in the National Family Planning Programme. Based on the Indian studies CuT 200 was also recommended. Studies have indicated the advantage of intrauterine devices (IUD); they are long acting, relatively easily removed and fertility returns rapidly after their removal. Recent studies have recommended CuT 200 for use up to 5 years. The combination of some plant products i.e. Embelia ribes, Borax and Piper longum has been found to be safe and effective as a female contraceptive and the results of phase-I clinical trials are encouraging. Research work is going on in the country in various areas with special reference to hormonal contraceptive - a three monthly injectable contraceptive, immuno-contraceptives, antiprogestins, etc.

Seasonal and social correlates of fecal testosterone and cortisol levels in wild male muriquis (Brachyteles arachnoides)

Fecal testosterone and cortisol levels were analyzed from six wild male muriquis (Brachyteles arachnoides) over a 19-month period at the Estação Biológica de Caratinga in Minas Gerais, Brazil, to investigate the hormonal correlates of seasonal sexual behavior and environmental conditions. Group mean testosterone levels based on weekly samples from the six males did not differ between copulatory and noncopulatory periods or between rainy and dry seasons. Cortisol levels did change with copulatory periods, and were significantly higher during the second dry season, when mating continued following an exceptionally heavy rainy season, than during the first dry season, when mating ceased. Males exhibited individual variation in the timing of their hormone shifts relative to their sexual activity, but neither hormone levels nor sexual activity were related to male age. Despite individual differences in the timing of testosterone fluctuations around the onset and offset of the copulatory season, all males exhibited elevated cortisol concentrations following a slight increase in testosterone at the beginning of the copulatory season. Both the lack of significant changes in testosterone levels with the onset of the rainy and copulatory season and the lack of prebreeding increases in cortisol may be related to the low levels of overt aggression displayed by male muriquis over access to mates.

Suppression of testicular and epididymal functions in a non-human primate (bonnet monkey) by combined administration of a gonadotropin-releasing hormone antagonist and testosterone buciclate

The ability of a long-acting androgen, testosterone buciclate (TB), to induce suppression of testicular and epididymal sperm functions when given in combination with a potent GnRH antagonist (Antide) either on day 1 or 45 of Antide administration (days 1-90) as well as the ability of TB to maintain Antide-induced suppression of spermatogenesis were evaluated in adult bonnet monkeys. A group of untreated animals (group I) acted as controls. All animals given Antide and androgen simultaneously (group II) became azoospermic but at different times. When androgen administration was delayed 45 days after start of Antide treatment (group III), the mean sperm concentration remained in the normospermic range and only three animals became azoospermic. Antide given alone (group IV) induced azoospermia in three animals and oligospermia in the remaining animals; spermatogenesis recovered when Antide was withdrawn and TB was injected. In all Antide-treated animals (groups II-IV), non-motile spermatozoa or sperm with non-progressive motility and poor gel penetrability were seen in the ejaculate.