The aims of this study were (a) to establish the occurrence, duration and intensity of behavioral estrus symptoms, and (b) to determine the relationship between behavioral estrus symptoms with the total estrogen profiles in cycling Murrah buffaloes (n=10) subjected to Doublesynch protocol (0 PGF2α, 2 GnRH, 9 PGF2α and 11 GnRH). After both GnRH injections, estrus and its behavioral signs were de...

We describe the preliminary characterization of GnRH-binding protein(s) in human placental cytosol. Samples were analysed by chromatography on Sephadex G25. Radiolabelled GnRH and its analogues elute significantly later than the total column volume (V(t)) on Sephadex G25 column chromatography. However, incubation of GnRH II or GnRH agonist tracers with human placental cytosol reduced the intact...

We investigated whether Jun N-terminal kinase (JNK) and p38 mediate gonadotropin subunit transcriptional responses to pulsatile GnRH in normal rat pituitaries. A single pulse of GnRH or vehicle was given to female rats in vivo, pituitaries collected, and phosphorylated JNK and p38 measured. GnRH stimulated an increase in JNK phosphorylation within 5 min, which peaked 15 min after GnRH (3-fold)....

BACKGROUND Gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) are involved in the reproductive cycle and regulate the secretion of sex steroids from the gonads. In mammals, GnRH1 is secreted as a hormone from the hypothalamus, whereas both GnRH1 and GnRH2 are present as neuropeptides in a variety of tissues. This review describes the role of ...

The effects of decreasing the frequency of pulsatile gonadotropin-releasing hormone (GnRH) stimulation on pituitary responsiveness were studied in (a) men with isolated GnRH deficiency who had achieved normal sex steroid levels during prior long-term pulsatile GnRH replacement and (b) perifused dispersed pituitary cells from male rats in the absence of sex steroids. In three groups of four GnRH...

Pope got it right, although amphioxus is a slimy ancestor to acknowledge. But what does this beast have to tell us about our origins? In this issue, Tello and Sherwood (1) propose that in amphioxus, the most basal chordate, four GnRH receptors are present: two that sit at the base of the invertebrate lineage and two at the base of the vertebrate lineage. Amphioxus, also known as the lancelet, g...

This study utilized a newly developed antiserum, specific for lamprey gonadotropin-releasing hormone III (l-GnRH-III), to determine the following: in which regions of the rat hypothalamus the neuronal perikarya producing l-GnRH-III are localized; and whether this peptide, known to selectively induce follicle-stimulating hormone release, is coexpressed in neurons containing mammalian luteinizing...

BACKGROUND/AIMS Kisspeptin is the major excitatory regulator of gonadotropin-releasing hormone (GnRH) neurons and is responsible for basal GnRH/LH release and the GnRH/LH surge. Although it is widely assumed, based on mutations in kisspeptin and Kiss1R, that kisspeptin acts to sustain basal GnRH neuronal activity, there have been no studies to investigate whether endogenous basal kisspeptin ton...

The hypothalamus, pituitary, and gonads coordinate to direct the development and regulation of reproductive function in mammals. Control of the hypothalamic-pituitary-gonadal axis is dependent on correct migration of gonadotropin-releasing hormone (GnRH) neurons from the nasal placode to the hypothalamus, followed by proper synthesis and pulsatile secretion of GnRH, functions absent in patients...

Gonadotropin-releasing hormone (GnRH) is present in nervus terminalis neurons in chemosensory nerve fascicles in vertebrates. In rodents, the majority of GnRH fibers are located within vomeronasal nerves. We have shown that GnRH can alter vomeronasal receptor neuron responses to odors. In this study, using prairie voles, we tested the hypotheses that (i) GnRH-immunoreactive (-ir) neurons projec...