BACKGROUND FSH hypersecretion occurs in mothers of dizygotic (DZ) twins. Twinning is inherited via both sexes and transmitted through the female. FSH hypersecretion may thus occur in male DZ twins. METHODS We assayed FSH and its counter-regulatory hormone, Inhibin B, in 108 adult male DZ and 100 monozygotic (MZ) twins (as controls) and compared our results to published norms. RESULTS Inhibi...

OBJECTIVE To evaluate the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels in early follicular phase throughout the reproductive years. METHOD FSH and LH concentrations were determined by radioimmunoassay (RIA). Linear and polynomial regressions were carried out considering basal FSH as the dependent and age as the independent variable. RESULTS FSH levels increased thr...

BACKGROUND To compare the clinical results and the cost-effectiveness of using the aromatase inhibitor, letrozole, in conjunction with FSH and FSH alone for controlled ovarian stimulation (COS) in patients undergoing intrauterine insemination (IUI) for a variety of indications. METHODS Four hundred and thirty-two consecutive patients who underwent 872 IUI cycles were included. The study popul...

The aim of this study was to evaluate the effect of pertussis toxin (PTX) on the depolarizing component of the action of follicle stimulating hormone (FSH) on the membrane potential (MP) of Sertoli cells, which is linked to the rapid entry of Ca(2+) into cells and to the Ca(2+)-dependent transport of neutral amino acids by the A system. This model allowed us to analyze the involvement of Gi pro...

BACKGROUND To test the effects of progressively decreasing dosages of exogenous LH we combined various amounts of HMG, containing FSH, LH and HCG, and highly purified (HP) FSH to treat 120 GnRH agonist-suppressed infertile female patients as candidates for controlled ovarian stimulation (COS). METHODS Subjects were randomly assigned to four treatment groups that received the following daily i...

The critical influence of follicle stimulating hormone (FSH) on male fertility relates both to its impact on Sertoli cell proliferation in perinatal life and to its influence on the synthesis of Sertoli cell-derived products essential for germ cell survival and function in the developing adult testis. The nature and timing of this shift of germ cells to their reliance on specific Sertoli cell-d...

BACKGROUND Bone morphogenetic protein 15 (BMP15) is a growth factor derived from oocyte and is essential for in vivo ovarian follicular growth and in this study, its effects on the improvement of growth and development of follicles during in vitro culture of neonatal mouse ovaries was investigated. METHODS Two week old mice were cultured for 7 days in the basic culture media with or without f...

The sequential changes in the concentration and pattern of circulating luteinizing hormone (LH) and follicle-stimulating hormone (FSH)(1) following bilateral ovariectomy were determined in 10 premenopausal women. The initial (1st wk) and delayed (3 wk) secretory responses of serum LH and FSH as related to the phases of the menstrual cycle were examined. Ovariectomy during follicular phase was a...

Current ovarian stimulation regimens for IVF are complex and not without risk. Increasing our knowledge of the physiology of follicle development and dominant follicle selection may enable the design of less complex, safer and cheaper ovarian stimulation regimens for IVF. Decremental serum FSH concentrations during the follicular phase of the menstrual cycle are required for single dominant fol...

A dynamic partnership between follicle-stimulating hormone (FSH) and activin is required for normal Sertoli cell development and fertility. Disruptions to this partnership trigger Sertoli cells to deviate from their normal developmental pathway, as observed in inhibin α-knockout (Inha-KO) mice, which feature Sertoli cell tumours in adulthood. Here, we identified the developmental windows by whi...