In various methods that have been reported for the preparation of pituitary gonadotropin, such as those of Jensen, Simpson, Folksdorf, and Evans (1) and Chow, van Dyke, and Greep (2), the active material is obtained either by precipitation with organic liquids or by salt precipitation, after which the gonadotropin or gonadotropins are separated from the precipitate. However, Fevold, Lee, Hisaw,...

To study the involvement of gonadotropin-releasing hormone (GnRH) in glycosylation of circulating gonadotropin isoforms in anorexia nervosa (AN), 14 amenorrhoic patients with AN, 14 age-matched volunteers in early follicular phase, and five normal-weight re-fed patients with AN were investigated under baseline conditions and after acute administration of GnRH. Plasma gonadotropins were assayed ...

Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) levels were examined during consecutive reproductive states in Mongolian gerbils. The results indicate that FSH, LH, and PRL levels peak at proestrus, estrus, and diestrus, respectively. During early gestation in primiparous gerbils, gonadotropin levels were the lowest on day 6. This was followed by an incre...

Gonadotropin binding and stimulation of cyclic adenosine 3':5'-monophosphate (cyclic AMP) formation and testosterone synthesis were studied in collagenase-dispersed interstitial cells from the adult rat testis. Binding of 125I-human chorionic gonadotropin (hCG) by isolated Leydig cells was of high affinity (Ka = 10(10) M-1) and low capacity, equivalent to approximately 6000 sites/cell. The bind...

This study investigated the participation of MAPK in the resumption of meiosis [germinal vesicle breakdown (GVB)] in oocytes and cumulus expansion using oocyte-cumulus cell complexes (OCC) from Mos-null mice (Mos(tm1Ev)/Mos(tm1Ev), hereafter Mos(-/-)). MAPK activity was not detected in Mos(-/-) oocytes whether they matured in vivo or in vitro, with or without gonadotropin stimulation. Therefore...

Gonadotropin-releasing hormone (GnRH) acts at gonadotropes to direct the synthesis of the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The frequency of GnRH pulses determines the pattern of gonadotropin synthesis. Several hypotheses for how the gonadotrope decodes GnRH frequency to regulate gonadotropin subunit genes differentially have been proposed. However...

Plasma membranes isolated from bovine corpora lutea showed specific binding with 1251-human chorionic gonadotropin and 1251-human luteinizing hormone; unlabeled hormones competitively inhibited the binding. The binding of the 1251-human chorionic gonadotropin to the receptor was a saturable phenomenon and the half-saturation was attained at a concentration of 4 X lo-r0 M. Maximum hormone recept...

Gonadotropins are routinely administered to produce multiple oocytes for clinical in vitro fertilization (IVF) treatment, laboratory research, and livestock industries. Studies in mice have shown gonadotropin stimulation using equine chorionic gonadotropin (eCG) affects the endometrium, implantation, and fetal development. Evidence from clinical studies also indicates that stimulation with reco...

Background: This retrospective study evaluated the effect of profound pituitary suppression with oral contraceptive pill (OCP) pretreatment in gonadotropin-releasing hormone (GnRH) antagonist cycles stimulated with recombinant follicle stimulating hormone plus highly purified human menopausal gonadotropin. Methods: The analysis included women aged 20-46 years (N=318) who utilized OCP pretreatme...

The existence of a hypothalamic gonadotropin-inhibiting system has been elusive. A neuropeptide named gonadotropin-inhibitory hormone (GnIH, SIKPSAYLPLRF-NH(2)) which directly inhibits gonadotropin synthesis and release from the pituitary was recently identified in quail hypothalamus. Here we identify GnIH homologs in the human hypothalamus and characterize their distribution and biological act...