Evaluation of uterine receptivity after gonadotropin releasing hormone agonist administration as an oocyte maturation trigger: a rodent model.

In natural cycle or minimal stimulation cycle IVF, buserelin acetate (buserelin), a gonadotropin-releasing hormone agonist, is often used as a maturation trigger; however, its effect on pregnancy outcomes remains unclear. Therefore, in the present study, we compared uterine receptivity in buserelin-administered mice with that in human chorionic gonadotropin (hCG)-administered mice during the peri-implantation period. Implantation, decidualisation, and term-pregnancy were impaired following hCG, but not buserelin administration. hCG stimulated the synthesis and secretion of progesterone and oestradiol, whereas ovarian steroidogenesis in the buserelin-treated group was comparable with that in the control group. Furthermore, similar to the observation in controls, the buserelin-treated group exhibited activation of progesterone receptor signalling and inhibition of oestrogen receptor signalling in the endometrial epithelium on the day of implantation. However, epithelial progesterone signalling was not detected, and a high expression of genes downstream to oestrogen was observed on day 4 following hCG administration. These results suggest that buserelin administration does not impact uterine receptivity as it did not affect ovarian steroidogenesis and endometrial steroid signalling. Therefore, buserelin is preferred as an oocyte maturation trigger to optimise uterine receptivity during treatments involving timed intercourse, intrauterine insemination, or fresh embryo transfer following in vitro fertilisation.

Short-term buserelin administration induces apoptosis and morphological changes in adult rat testes.

PURPOSE: To investigate the effect of buserelin on gonadal structure and function in adult male rats. METHODS: Twenty-four adult Wistar male rats were divided into three groups: two treated groups and controls. The first and second treated groups received 300 (low dose) and 500 (high dose) µg/kg buserelin, respectively, and the control group received normal saline. All groups were treated subcutaneously for five days. RESULTS: The seminiferous tubular epithelial thickness was significant decreased in the treated groups compared with those in the control. There was a significant increase in apoptotic cell death in high dose treated group compared with low dose treated and control groups. No significant difference in serum testosterone level was observed after one month in the three groups. CONCLUSION: Buserelin induces apoptotic cell death and decreased diameter and epithelium thickness of seminiferous tubules in the adult rat testes.

Short-term buserelin administration induces apoptosis and morphological changes in adult rat testes

Abstract Purpose: To investigate the effect of buserelin on gonadal structure and function in adult male rats. Methods: Twenty-four adult Wistar male rats were divided into three groups: two treated groups and controls. The first and second treated groups received 300 (low dose) and 500 (high dose) µg/kg buserelin, respectively, and the control group received normal saline. All groups were treated subcutaneously for five days. Results: The seminiferous tubular epithelial thickness was significant decreased in the treated groups compared with those in the control. There was a significant increase in apoptotic cell death in high dose treated group compared with low dose treated and control groups. No significant difference in serum testosterone level was observed after one month in the three groups. Conclusion: Buserelin induces apoptotic cell death and decreased diameter and epithelium thickness of seminiferous tubules in the adult rat testes.

Effects of the intensity of downregulation on outcome of in vitro fertilization and embryo transfer.

Gonadotropin releasing hormone agonists (GnRHa) are commonly used during in vitro fertilization and embryo transfer (IVF/ET) treatment cycles to downregulate the hypothalamic-pituitary-ovarian axis prior to ovarian stimulation with gonadotropins. It has been suggested that profound downregulation may have an adverse effect on IVF/ET outcome. The aim of this study was to examine the relationship between the degree of downregulation and IVF/ET outcome. A retrospective analysis was performed on 151 IVF/ET cycles conducted over a six month period. Intensity of downregulation was assessed using measurements of serum concentrations of luteinizing hormone (LH) and estradiol (E2) made at the end of a two week downregulation period. There was no correlation between serum concentration of LH (whether used alone or in combination with E2) and IVF/ET pregnancy rates. However, those subjects who were more suppressed according to the E2 concentration (< 148 pmol/l, [median]) required significantly more gonadotropins (3306 IU versus 2863 IU, p < 0.05) and took longer for follicles to reach maturity (10.9 days versus 9.7 days, p < 0.05). They also had a lower pregnancy rate per embryo transfer (10.4% versus 28.6%, p < 0.05) compared with those having a higher basal E2 concentration. We conclude from this study that the basal serum E2 concentration rather than the LH concentration is a more sensitive indicator of the intensity of downregulation by GnRHa and it may be a better predictor of IVF outcome.

Preventive effects of a herbal medicine on bone loss in rats treated with a GnRH agonist.

The study was designed to evaluate the effects of a traditional Chinese herbal medicine Hochu-ekki-to (Bu-zong-yi-qi-tang), which was composed of 10 herbal medicines and had been used for the treatment of oligospermia and as a postoperative medication in Japan, on bone loss in rats treated with a gonadotropin-releasing hormone (GnRH) agonist. Female rats at 40 weeks of age were divided into 4 groups of 8 rats each. In the three experimental groups, each animal received subcutaneous injections of the long-acting GnRH agonist, buserelin acetate, once every four weeks throughout the experiment. Beginning at 48 weeks of age, the experimental groups were given diets containing conjugated estrogens or Hochu-ekki-to for 8 weeks. The administration of the GnRH agonist reduced the bone mineral density in the whole femur to 91.0% of that in the control group. However, administration of conjugated estrogens and Hochu-ekki-to increased the serum concentrations of estradiol 16.8- and 5.3-fold respectively compared with concentrations in the GnRH agonist-treated group, resulting in the augmentation of the bone mineral density to 110.3% and 106.2% respectively. These findings indicate that Hochu-ekki-to enhances the reduced bone mineral density and causes a slight elevation of the serum estradiol levels in the chemically castrated rats.

Conservative management for perimenopausal women with uterine leiomyomas using Chinese herbal medicines and synthetic analogs of gonadotropin-releasing hormone.

The effects of a long-term intranasal administration of each of the gonadotropin-releasing hormone analogs, buserelin and nafarelin on uterine leiomyomas after conservative treatment using Chinese herbal medicines, Keishi-bukuryo-gan and Shakuyaku-kanzo-to were investigated in 30 perimenopausal women with leiomyomas. Hypermenorrhea and/or dysmenorrhea as a chief complaint was moderately improved by the treatment using Chinese herbal medicines in more than 60% of the patients with less than fist-sized leiomyomas, but not the over fist-sized. Afterwards, continuous treatment using analogs produced a long-term reduction in leiomyomas (less than 60%) along with decreases in the serum levels of luteinizing hormone, follicle-stimulating hormone, estradiol, and the tumor marker CA-125, and adverse effects including slight boneloss. Long-term treatment using Chinese herbal medicines and gonadotropin-releasing hormone analogs for the management of uterine leiomyomas could be beneficial for patients a few years before menopause, though possible side effects of this treatment should be monitored.

Buserelin. A review of its pharmacodynamic and pharmacokinetic properties, and clinical profile.

The gonadotrophin releasing hormone (GnRH) [luteinising hormone-releasing hormone (LHRH); gonadorelin] agonist buserelin is a promising new agent in the treatment of a variety of disorders in gynaecology and andrology, paediatrics and oncology. While a single dose of buserelin stimulates the release of pituitary gonadotrophins, multiple doses produce reversible pituitary desensitisation, and this specific blockade of gonadotrophin support to the gonads provides the basis for the drug's efficacy in conditions dependent on sex hormone secretion. Thus, buserelin provides comparable efficacy to orchidectomy or high dose estrogens in the treatment of hormone-sensitive prostate cancer and exhibits a lower incidence of adverse effects. During the early phase of treatment it may be particularly useful in combination with antiandrogens. Buserelin also appears promising in hormone-sensitive premenopausal breast cancer. Extensive studies have proven the value of buserelin in endometriosis, where it produces a transient remission with gradual recurrence of the disease on cessation of treatment. Surgical intervention is necessary in severe disease after buserelin-induced involution of the lesions. In patients with uterine leiomyoma, preliminary data suggest that buserelin may be beneficial in rendering surgery more conservative by reducing fibroid size, although it appears unlikely to preclude surgical intervention. The use of buserelin to induce a state of reversible hypogonadotrophism before administration of exogenous gonadotrophins is a promising strategy in the treatment of infertility associated with polycystic ovary syndrome and other conditions of infertility with underlying ovarian dysfunction; such a strategy also clearly enhances the efficiency of in vitro fertilisation programmes. Initial studies suggest its potential usefulness as a female contraceptive when administered intermittently in conjunction with a progestogen. Buserelin represents a first-line treatment of central precocious puberty. In endometriosis the adverse effect profile of buserelin is generally favourable, with hypoestrogenic effects such as hot flushes and vaginal dryness, and decreased libido, predominating. There is no apparent detrimental effect on lipid metabolism. The potential for adverse hypoestrogenic effects on bone mineral content with long term administration remains to be clarified. Thus, the GnRH agonist buserelin represents an advance in the treatment of a variety of gynaecological and andrological as well as paediatric and oncological conditions, infertility and other sex-hormone dependent conditions, with a low incidence of adverse treatment effects.