OBJECTIVES Gonadotropin-releasing hormone (GnRH) stimulates immune responses; therefore, antagonizing GnRH with cetrorelix may have anti-inflammatory effects. The aim of this study was to assess short-term cetrorelix therapy in rheumatoid arthritis (RA) patients. METHOD In this proof-of-concept, randomized, double-blind study involving 99 patients with active, long-standing RA, 48 patients re...

We investigated the direct effects of LH-releasing hormone (LH-RH) antagonist, Cetrorelix, on the growth of HTOA human epithelial ovarian cancer cell line. RT-PCR revealed the expression of mRNA for LH-RH and its receptor in HTOA cells. Cetrorelix, at concentrations between 10(-9) and 10(-5) M, exerted a dose-dependent antiproliferative action on HTOA cells, as measured by 5-bromo-2'-deoxyuridi...

The mechanisms through which LH-RH antagonists suppress gonadotroph functions and LH-RH receptor (LH-RH-R) production are incompletely understood. To elucidate these mechanisms, we investigated the effects of Cetrorelix on the mRNA expression of pituitary LH-RH-R and luteinizing hormone (LH) secretion in three experimental systems with different pituitary LH-RH environments. Ovariectomy induced...

Natural cycles were abandoned in in-vitro fertilization (IVF) embryo transfer, due to premature luteinizing hormone (LH) surges--and subsequent high cancellation rates. In this study, we investigated the administration of a new gonadotrophin-releasing hormone antagonist (Cetrorelix) in the late follicular phase of natural cycles in patients undergoing IVF and intracytoplasmic sperm injection (I...

Electrospray ionization mass spectrometry (ESI-MS) was used to evaluate the structure of cetrorelix and the related impurities generated throughout the solid phase peptide synthesis (SPPS) reactions by Fmoc strategy. It was concluded that these by-products are formed as a result of incomplete removal of the protecting groups placed on side chains during synthesis. The impurity with 56 Da mass d...

UNLABELLED Conventional diagnostic procedures failed to provide a definitive diagnosis in a 15 year-old girl presenting with severe hirsutism, oligomenorrhea, and markedly elevated serum testosterone levels. To examine whether androgen overproduction was luteinizing hormone (LH) dependent and thus likely of ovarian origin we performed a new test to suppress LH secretion based on the use of Cetr...

BACKGROUND We report our experience on the efficacy of a new regimen of the GnRH antagonist, cetrorelix, and recombinant FSH, Gonal-F, for controlled ovarian stimulation in a donor oocyte programme. METHODS AND RESULTS Six oocyte donors were commenced on Gonal-F (150 IU) and two on Gonal-F 225 IU daily on day 4 together with cetrorelix 0.25 mg daily on day 8 until the day of administration of...

BACKGROUND For male hormonal contraception, combined administration of gonadotrophin-releasing hormone (GnRH) antagonists and androgens effectively suppresses spermatogenesis to azoospermia. In non-human primates this suppression can be maintained more easily by androgens alone. METHODS A clinical trial with six healthy volunteers was performed to test this approach in man. Loading doses of 1...

A gradient reversed-phase high performance liquid chromatography (HPLC) method was developed for the assay of cetrorelix acetate, a synthetic decapeptide with gonadotropin-releasing hormone (GnRH) antagonistic activity used in infertility treatment. The HPLC method, which is used to determine cetrorelix in bulk and pharmaceutical dosage forms, was validated per ICH guidelines. The chromatograph...

Objective: Both gonadotropin-releasing hormone (GnRH) analogs and antagonists have been used for pituitary desensitization during controlled ovarian hyperstimulation (COH). We aimed to determine the minimum effective daily dose of GnRH antagonist in women undergoing COH. We also compared the efficiency of a GnRH antagonist and a GnRH agonist. Materials and Methods: Women undergoing in vitro fer...