Search results for "Gonadotropin-releasing hormone"
showing 10 items of 52 documents
Expression and regulation of mPer1 in immortalized GnRH neurons.
2003
Hypothalamic GnRH (gonadotropin-releasing hormone) neurons play a critical role in the initiation and maintenance of reproduction competence. Using the mouse GnRH neuronal cell line, GT1-7, we have characterized the expression of the gene mPer1, a recognized key element of the mammalian circadian clockwork. Both mPer1 transcripts and the 136 kDa mPER1 gene product could be detected in these cells. Immunocytochemical analysis also confirmed expression of mPER1 both in vitro and in vivo in GnRH neurons. Activation of cyclic AMP signalling pathways in vitro elevated GnRH secretion as well as mPer1 expression and nuclear mPER1 immunoreactivity. As mPER1 is known to feedback on transcriptional a…
Depressive effect of LHRH on the numbers of "synaptic" ribbons and spherules in the pineal gland of diestrous rats.
1983
Previous studies have shown that LHRH or LHRH-like substances are present in the pineal gland. In order to investigate whether exogenous LHRH may affect the pineal gland, in the present study the effects of a single dose of LHRH (1 microgram, i.p.) on pineal "synaptic" ribbons and spherules as well as serum melatonin levels were examined in diestrous Wistar rats. One hour after the injection both ribbons and spherules exhibited a statistically significant decrease in number. Serum melatonin levels were not affected. It is concluded that humoral feedback mechanisms may exist between the hypothalamus and the pineal gland.
Binding of Cu2+, Zn2+, and Ni(2+)-GnRH complexes with the rat pituitary receptor.
1997
Complex of copper with the gonadotropin-releasing hormone, GnRH, competed more efficiently for the GnRH receptor than native GVRH, while complexes of nickel with GnRH and zinc with GnRH had slightly lower affinity. Copper ion added to the incubation mixture inhibited the buserelin binding to the receptor.
Human Oviductal Gonadotropin-Releasing Hormone: Possible Implications in Fertilization, Early Embryonic Development, and Implantation1
2000
The oviduct is host to gametes and early embryos at a critical point in their lives. It is clear that the interactions of gametes/early embryo with the maternal oviduct in an autocrine and paracrine manner provide a microenvironment that enhances fertilization, early embryonic development, and implantation. Moreover, there is considerable evidence that an extrahypothalamic GnRH may play a substantial role as a molecular autocrine/paracrine regulator in these events. Gametes and preimplantation embryos express GnRH and GnRH receptor at both messenger ribonucleic acid (mRNA) and protein levels. However, whether GnRH is produced by the human oviduct has not yet been demonstrated. We used RT-PC…
Increased LH and FSH release from the anterior pituitary of ovariectomized rat, in vivo, by copper-, nickel-, and zinc-LHRH complexes.
1992
Abstract The effect of Cu 2+ , Ni 2+ , Zn 2+ and their complexes with LHRH on the release of luteinizing hormone (LH) and follicle stimulating hormone (FSH) was estimated in in vivo experiments with the use of the method proposed by Ramirez and McCann. Ovariectomized, estradiol, and progesterone pretreated rats were injected intraveneously either with LHRH alone, a metal ion alone, a mixture of metal and hormone, or a metal-LHRH complex. A metal alone or a mixture of it with LHRH did not affect gonadotropin release at all or no more than LHRH alone. However, the complex of Cu 2+ with LHRH brought about a high release of LH and even higher release of FSH. This indicates that copper complex i…
Effect of Cetrorelix on sperm morphology during migration through the epididymis in the cynomolgus macaque (Macaca fascicularis)
2000
The importance of the cynomolgus monkey as a model for human reproductive medicine prompted this examination of epididymal sperm morphology. Computer-aided sperm morphological analysis was used for the first time to provide morphometric data on sperm heads as they traversed the epididymal duct of Macaca fascicularis. The duct was divided into six regions, starting close to the testis (proximal) and ending close to the vas deferens (distal). To determine the androgen-dependence of the changes, one group of animals received a GnRH-antagonist (Cetrorelix, Asta Medica, Frankfurt, Germany) to induce testicular regression and lower epididymal androgens, while a control group received only vehicle…
Conservative Management of Atypical Endometrial Hyperplasia and Early Endometrial Cancer in Childbearing Age Women.
2022
Total hysterectomy and bilateral adnexectomy is the standard treatment for atypical endometrial hyperplasia and early-stage endometrial cancer. However, the recommended surgical treatment precludes future pregnancy when these conditions are diagnosed in women in their fertile age. In these patients, fertility-sparing treatment may be feasible if the desire for childbearing is consistent and specific conditions are present. This review summarizes the available evidence on fertility-sparing management for atypical endometrial hyperplasia and early-stage endometrial cancer. Historically, oral progestins have been the mainstay of conservative management for atypical endometrial hyperplasia and …
Anti-androgens for the treatment of hirsutism.
2002
Many alternatives exist for treating hirsutism. Based on an analysis of scientific literature and on the experiences of the author, the most common anti-androgen agents are discussed in this review. Androgen receptor blockers (cyproterone acetate, flutamide and spironolactone), 5 alpha-reductase inhibitors (finasteride) and androgen-suppressing agents (gonadotrophin-releasing hormone [GnRH] agonists, oestroprogestins, corticosteroids and insulin-sensitising agents) are evaluated and compared. The importance of diagnosis in choosing the most appropriate anti-androgen treatment is also discussed.
Goserelin acetate to avoid hysterectomy in pre-menopausal women with fibroids requiring surgery
1999
Objective: To obtain information on the efficacy of repeated short cycles of GNRH agonist treatment in order to avoid hysterectomy in near-menopausal women with symptomatic fibroids. Study design: 72 pre-menopausal women (mean age 50 years) with one or more uterine fibroids >10 cm in diameter, symptomatic menorrhagia lasting three months or more and haemoglobin=9 g/dl entered the study. The patients were randomized with ratio of approximately 1:4 to: (a) immediate surgery; or (b) treatment with goserelin acetate. Patients randomized to goserelin acetate received a first cycle of 3.6 mg depot once every 28 days for four months. They were followed-up for three years. If menorrhagia was observ…
Endocrinology and physiology of pseudocyesis
2013
This literature review on pseudocyesis or false pregnancy aims to find epidemiological, psychiatric/psychologic, gynecological and endocrine traits associated with this condition in order to propose neuroendocrine/endocrine mechanisms leading to the emergence of pseudocyetic traits. Ten women from 5 selected studies were analyzed after applying stringent criteria to discriminate between cases of true pseudocyesis (pseudocyesis vera) versus delusional, simulated or erroneous pseudocyesis. The analysis of the reviewed studies evidenced that pseudocyesis shares many endocrine traits with both polycystic ovarian syndrome and major depressive disorder, although the endocrine traits are more akin…