BACKGROUND The effect of recombinant human LH (r-hLH; lutropin alfa) in women undergoing controlled ovarian stimulation with recombinant human FSH (r-hFSH) prior to IVF was investigated. METHODS After down-regulation with the GnRH agonist, buserelin, 114 normo-ovulatory women (aged 18-37 years) received r-hFSH alone until the lead follicle reached a diameter of 14 mm. Patients were then rando...

Human reproduction is dependent upon the actions of follicle-stimulating hormone (hFSH), luteinizing hormone (hLH), and chorionic gonadotropin (hCG). While the alpha subunits of these heterodimeric proteins can be interchanged without effect on receptor-binding specificity, their beta subunits differ and direct hormone binding to either LH/CG or FSH receptors. Previous studies employing chemica...

Rat testis tissue receptor assays were utilized to study the kinetics of dissociation of human follicle-stimulating hormone (hFSH) and luteinizing hormone (hLH) under varying conditions of urea concentration and pH. In these competitive protein binding assays, 125I-hFSH and 125I-hLH were the radioligands and hormone dissociation was followed by a decrease in the ability of the dissociating horm...

Reversed-phase high-performance liquid chromatography (RP-HPLC) was compared with the classical Steelman-Pohley bioassay (BA), based on animal use, for the determination of human follicle-stimulating hormone (hFSH) biological activity. A linear relationship (BA(IU)=0.9925 RP-HPLC(IU)-1.3165) with a highly significant correlation (r=0.9371; p<0.0001; n=24) was found for these two methods for six...

Immature calf testes were found to be an unusually rich source of follitropin (FSH) receptors. Particulate fractions derived from such testes bound 32% of added biologically active radiolabeled human FSH (12”I-labeled hFSH) and had a binding capacity of 52 x lo-l4 mol/mg of protein. These values are considerably higher than those previously reported for FSH receptors in other types of beef or m...

The efficacy of follicle stimulating hormone (FSH) as an alternative to luteinizing hormone (LH)/human chorionic gonadotrophin (HCG) for the initiation of periovulatory events in primate follicles is unknown. A single bolus of 2500 IU recombinant (r)-hFSH was compared to 1000 IU r-HCG for its ability to promote oocyte nuclear maturation and fertilization, granulosa cell luteinization and corpus...

A reversed-phase high-performance liquid chromatography (RP-HPLC) method for the qualitative and quantitative analysis of intact human follicle-stimulating hormone (hFSH) was established and validated for accuracy, precision and sensitivity. Human FSH is a dimeric glycoprotein hormone widely used as a diagnostic analyte and as a therapeutic product in reproductive medicine. The technique develo...

Hyperstimulation of ovarian function with human FSH (hFSH) attenuates the preovulatory surge of LH. These experiments aimed at investigating the mechanism of ovarian-mediated FSH suppression of the progesterone (P(4)) receptor (PR)-dependent LH surge in the rat. Four-day cycling rats were injected with hFSH, oestradiol benzoate (EB) or vehicle during the dioestrous phase. On pro-oestrus, their ...

Administration of human FSH (hFSH) to cyclic rats during the dioestrous phase attenuates progesterone receptor (PR)-dependent events of the preovulatory LH surge in pro-oestrus. The increased bioactivity of the putative ovarian gonadotropin surge inhibiting/attenuating factor induced by hFSH treatment is not associated with a decrease in PR protein expression, and the possibility of its associa...