routinely, a bolus of 5.000-10.000 iu human chorionic gonadotropin (hcg) is usedfor the final follicular maturation and ovulation as a standard method. hcg has thesame effect of luteinizing hormone (lh) with long half-life. it has the longlutheotrophic effect which increases the risk of ovarian hyper stimulation syndrome(ohss). recently, gonadotropin-releasing hormone agonist (gnrh-a) trigger h...

Neuropeptide Y (NPY) stimulates the release of GnRH in an estrogen (E2)-dependent manner, which is important in generating preovulatory GnRH surges. We tested the hypothesis that E2 up-regulates NPY's actions by stimulating NPY Y1 receptor (Y1r) gene expression through a mechanism mediated by E2's ability to induce progesterone (P) receptors (PRs). In initial experiments, a specific Y1r antagon...

Background: Infertility problem affects young couples. One of the known causes of spermatogenic disorder is chemotherapy in patients with cancer. Since dividing cells are mainly affected by anticancer drugs, the aim of the present study is to investigate the preventive effect of GnRH antagonist on spermatogenic cell apoptosis produced by anticancer drug. Materials and Methods: In the present st...

Atresia, a degenerative process through which many follicles are removed from the growing pool, involves apoptotic changes in the follicular granulosa cells. To identify histochemical markers of early stages of atresia, an in-vivo rat model was used which allowed the study of atresia of pre-ovulatory follicles in a synchronized and chronological order. By blocking the pre-ovulatory luteinizing ...

Objective This retrospective study compared the effect of the luteal phase ovarian stimulation protocol (LP group) with the gonadotrophin-releasing hormone (GnRH) antagonist protocol (AN group) in women with poor ovarian responses. Methods Ovarian stimulation was initiated with 225 IU of human gonadotrophin (hMG) daily. When the dominant follicle diameter exceeded 13 mm, 0.25 mg of a GnRH antag...

Glucose regulates energy homeostasis and reproductive function within the hypothalamus. The underlying mechanisms responsible for glucose regulation of GnRH gene transcription were investigated using a novel murine immortalized, adult-derived hypothalamic cell line, mHypoA-GnRH/GFP. Analysis of GnRH mRNA synthesis and secretion following agonist treatment demonstrated that the mHypoA-GnRH/GFP c...

Introduction: Gonadotropin-releasing hormone (GnRH) agonist triggers are increasingly used in antagonist vitro fertilization (IVF) cycles to prevent ovarian hyperstimulation syndrome (OHSS) following a robust response. The luteolytic effects of GnRH agonists inhibit implantation or spontaneous pregnancy, warranting freezing available blastocysts for future transfer after the risk OHSS subsides....

Photodynamic therapy uses a combination of light, oxygen, and a photosensitizer to induce the death of malignant cells. To improve the selectivity of a photosensitizer toward cancerous cells that express gonadotropin-releasing hormone (GnRH) receptors, protoporphyrin IX (PpIX) was conjugated to a GnRH agonist, [d-Lys6]GnRH, or to a GnRH antagonist, [d-pGlu1, d-Phe2, d-Trp3, d-Lys6]GnRH. The con...

Gonadotropin-releasing hormone (GnRH) neurons are the primary central regulators of fertility, receiving input from GABAergic afferents via GABA(A) receptors. We tested whether metabotropic glutamate receptors (mGluRs) regulate GABA transmission to GnRH neurons and GnRH neuronal firing pattern. Whole-cell recordings were performed under conditions isolating ionotropic GABA postsynaptic currents...

BACKGROUND Our objective was to evaluate the effectiveness of clomiphene citrate (CC) vs. letrozole (L) plus human menopausal gonadotropin (hMG) in gonadotropin releasing hormone (GnRH) antagonist protocol in poor prognosis women with previous failed ovarian stimulation undergoing intracytoplasmic sperm injection (ICSI). MATERIALS AND METHODS This retrospective cohort study included cycles wi...