Hormonal male contraception requires an induction phase before azoospermia and contraceptive safety are achieved. The nature of spermatozoa that may be ejaculated during this induction phase was studied in a nonhuman primate. The GnRH antagonist Cetrorelix was administered daily to five cynomolgus monkeys to induce testicular regression, and the vehicle was given to five control animals. Within...

Recently, we could show that gonadotropin-releasing hormone (GnRH)-II antagonists induce apoptosis in human endometrial, ovarian, and breast cancer cells in vitro and in vivo. In the present study, we have ascertained receptor binding and effects of GnRH-II antagonists on mitogenic signal transduction and on activation of proapoptotic protein Bax. The GnRH-II antagonists tested showed EC50 valu...

Some analogues of gonadotropin-releasing hormone (GnRH) influence the in vitro proliferation of cultured human cells by complex interactions that are only partially understood. This study explored the effect of Triptorelin, a GnRH agonist, on the LNCaP and PC3 prostatic cell lines, which are, respectively, responsive and unresponsive to androgen stimulation. The toxicity and cell cycle modifica...

background: the differential efficacy between long gnrh agonist with antagonist can partly be due to the preexisting differences in the early antral follicles before ovarian stimulation. objective: to compare the effect of pretreatment by estradiol with gnrh antagonist on antral follicular size coordination and basal hormone levels in gnrh antagonist protocol. materials and methods: on cycle da...

– AIM: This prospective study was designed to assess whether the use of GnRH antagonists can improve the success rate of controlled ovarian stimulation (COS) in intrauterine insemination (IUI) treatments. PATIENTS AND METHODS: Eighty patients were divided into two groups: GnRH antagonist group (Group A, n=40) and control group (Group B, n=40). Patients in Group B underwent COS with recombinant ...

In order to compare the mechanism for the down regulation of the mRNA expression of pituitary receptors induced by GnRH antagonist (GnRHant) to that by GnRH agonist (GnRHa), we examined the effects of GnRHant (Cetrorelix, 333 mug/kg/day), GnRHa (leuprolide depot, 333 microg/kg), and GnRHant combined with GnRHa on LH response to exogenous GnRH, pituitary LH content, LH beta subunit mRNA, and GnR...

Photodynamic therapy (PDT) is a promising therapeutic modality which uses a photosensitizer to capture visible light resulting in phototoxicity in the irradiated region. PDT has been used in a number of pathological indications, including tumor. A key desirable feature of the photosensitizer is the high phototoxicity on tumor cells but not on normal cells. In this study, we conjugate a gonadotr...