Little is known about the neuroendocrine control of fertility in the horse. In this species, unusual features characterize the normal estrous cycle such as a prolonged preovulatory LH surge during the follicular phase and a distinctive FSH surge during the midluteal phase. This study investigated the distribution and hormonal identity of gonadotrophs in the pars distalis (PD) and pars tuberalis...

Background: Orexin A, a small-molecule peptide, can regulate female hormones, but limited evidence for its mechanism of activity exists in ovine. Aims: The objective of this study was to investigate the effect of orexin A on progesterone (P4) secretion in cultured granulosa of sheep follicles. Methods: Sheep ovarian granulosa were isolated and ...

The relative r\l=o^\lesof FSH and LH in ovulation induction in immature and adult cycling rats and hamsters have been evaluated. Both heterologous purified pituitary hormones and homologous crude pituitary extracts have been used as ovulatory stimuli in immature animals primed with PMSG. Well-characterized FSH and LH antisera have been used in the above model systems to achieve specific neutral...

In order to evaluate the effect of O2 tension on the in vitro maturation (IVM) and fertilization (IVF) process, 11 replicates of OPU/IVP were performed using 1092 viable oocytes obtained from 48 Bos indicus embryo donors of commercial herds. Cumulus-oocyte complexes (COCs) from each donor were homogeneously and randomly distributed across two treatments. The IVM was performed in TCM-199 with ov...

BACKGROUND The growing awareness of transfusion-associated morbidity and mortality necessitates investigations into the underlying mechanisms. Small animals have been the dominant transfusion model but have associated limitations. This study aimed to develop a comprehensive large animal (ovine) model of transfusion encompassing: blood collection, processing and storage, compatibility testing ri...

BACKGROUND Elevated follicle stimulating hormone (FSH) is associated with poor vaginal oocyte retrieval (VOR) outcomes and cycle cancellations but intercycle variability in basal FSH reportedly does not predict ovarian response. METHODS We conducted a retrospective cohort study of basal FSH (n = 15573 cycles) in couples (n = 9132) who initiated IVF cycle(s) with basal estradiol (E2) <100 pg/m...

In order to elucidate the presence of free FSH-beta and LH-beta and their relation to the native hormones, immunoreactive FSH (IR-FSH), IR-LH, IR-FSH-beta, and IR-LH-beta subunits in the rat anterior pituitary and serum from 1200hr of proestrous day to 0600hr of estrous day were measured by radioimmunoassay. The amounts of IR-FSH-beta found were always more than those explained by the cross-rea...