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...

Pokeweed antiviral protein (PAP) is a plant-derived, highly potent ribosome inactivating protein that causes inhibition of protein translation and rapid cell death. We and others have delivered this protein to various cell types, including cancer cells, using hormones to specifically target cells bearing the hormone receptor. Here, we compare binding and cytotoxicity of GnRH-PAP hormonotoxins p...

In assisted reproductive technology, medications and ovarian stimulation play a crucial role. The availability of gonadotrophins and GnRH analogues has allowed the tailoring of several stimulation schemes. The two most commonly used gonadotrophin forms are urinary hMG and recombinant FSH in combination with GnRH agonists or GnRH antagonists. Cycles stimulate with recombinant FSH appear to have ...