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Insulin-like factor 3 (INSL3) has an important role in the human reproductive system; however, its detailed function is still mysterious. We aimed to investigate the possibility of expression of RXFP2 receptor on human spermatozoa and to determine the anti-apoptotic and antioxidant mechanism derived the binding of INSL3 and RXFP2. In this experimental study, the expression/location of the RXFP2 receptor was determined on the spermatozoa of fertile and infertile men. Twenty samples from 20 fertile men were collected and divided into 6 parts (control group, and five groups treated with INSL3 10, 100, 250, 500, 1,000 ng/ml). DNA damage, active caspase, reactive oxygen species (ROS) and sperm parameters were evaluated by TUNEL, flow cytometry, optical microscope and computer-assisted sperm analysis. The expression of RXFP2 was confirmed by Western blot. Immunocytochemistry illustrated that this receptor is expressed in the posterior half of the spermatozoa's head. The INSL3 at concentrations of 500 and 1,000 ng/ml reduced the active caspase and mitochondrial ROS, and also reduced DNA fragmentation at 1,000 ng/ml. Besides, INSL3 500 and 1,000 ng/ml significantly increased the sperm motility. This study confirmed the presence of RXFP2 receptor in fertile and infertile men's spermatozoa, indicating the highly dose-dependent efficacy of the INSL3, which may have promising impacts on the in-vitro fertilisation outcomes., (© 2020 Blackwell Verlag GmbH.)

Oxygen consumption increases many times during exercise, which can increase reactive oxygen species. It negatively affects fertility in male athletes. Melatonin is exerting a regulatory role at different levels of the hypothalamic-pituitary-gonadal axis. However, there is no evidence that the protective effects of melatonin persist after long duration exercise on the spermatogenesis. Therefore, this study was conducted to examine the impacts of melatonin on the testis following the administration of swimming exercise. Rats were separated into five different groups, including Control, sham M: received the solvent of melatonin, M: received melatonin, S: the exercise protocol, MS: received melatonin and the exercise protocol. After 8 weeks, animals were scarified and antioxidant enzymes levels of testes, spermatogenic cells apoptosis and sperm quality were measured. Swimming decreased all parameters of spermatozoa. Nevertheless, melatonin could significantly improve the progressive motility of spermatozoa in MS rats. Swimming caused an increased apoptosis of S group and decreased all antioxidant enzymes. Melatonin could drastically reduce apoptosis and increased these enzymes. Therefore, melatonin seems to induce the production of antioxidant enzymes of testicular tissues and diminish the extent of apoptotic changes caused by forced exercise on the testis, which can, in turn, ameliorate the sperm parameters., (© 2017 Blackwell Verlag GmbH.)

This study evaluates the effect of melatonin on follicular dynamics in neonate vitrified ovarian grafts. Vitrified ovaries from neonate F1 hybrid mice, candidates for transplantation to treated or non-treated groups, were thawed under standard conditions with or without the addition of 100 μM melatonin, respectively. Following transplantation, melatonin (20 mg/kg/day) or saline solution was injected i.p. into the treated and the non-treated groups, respectively. Vaginal cytology to monitor estrogenic activity together with follicle survival and development in the ovary grafts was examined. The results showed that the sites of transplantation became obvious within the oestrous phase. Histological analysis showed that there was a dynamic of the ovogenesis process in the vitrified ovary grafts. However, in the ovary graft the empty cavity together with jumbled oocyte-granulosa complex in the non-treated group was higher than in the melatonin treated group. Overall, the number of primary follicles in the ovary grafts of both groups remained constant throughout the oestrous period. However, the treated ovary grafts contained more secondary follicles throughout the oestrous period in comparison to non-treated ovary grafts. The antral follicle rates were more marked in the melatonin treated group than in the non-treated group during the oestrous period, whereas at other days of the cycle no significant difference was observed. The fresh corpora lutea rates were significantly higher in the treatment group than in the non-treatment group. The study showed that there is a positive effect with melatonin resulting in more grafts restoring puberty. Furthermore, the associated increase in healthy follicles suggests that melatonin has a preventative ischaemia/antioxidant action and may be useful to follicles.