Anti-GHRH (full length) polyclonal antibody

The 2 structurally and functionally related peptides, neuropeptide B (NPB) and neuropeptide W (NPW), together with their receptor(s) (NPBWR1/NPBWR2) constitute the NPB/NPW system, which acts mainly on the central nervous system to regulate many physiological processes in mammals. However, little is known about this NPB/NPW system in nonmammalian vertebrates. In this study, the functionality and expression of this NPB/NPW system and its actions on the pituitary were investigated in chickens. The results showed that: 1) chicken NPB/NPW system comprises an NPB peptide of 28 amino acids (cNPB28), an NPW peptide of 23 or 30 amino acids (cNPW23/cNPW30), and their 2 receptors (cNPBWR1 and cNPBWR2), which are highly homologous to their human counterparts. 2) Using a pGL3-CRE-luciferase reporter system, we demonstrated that cNPBWR2 expressed in Chinese hamster ovary cells can be potently activated by cNPW23 (not cNPB28), and its activation inhibits the intracellular cAMP signaling pathway, whereas cNPBWR1 shows no response to peptide treatment, suggesting a crucial role of cNPBWR2 in mediating cNPW/cNPB actions. 3) Quantitative real-time PCR revealed that cNPW and cNPB are widely expressed in chicken tissues, including hypothalamus, whereas cNPBWR1 and cNPBWR2 are mainly expressed in brain or pituitary. 4) In accordance with abundant cNPBWR2 expression in pituitary, cNPW23 could dose dependently inhibit GH and prolactin secretion induced by GHRH and vasoactive intestinal polypeptide, respectively, in cultured chick pituitary cells, as monitored by Western blotting. Collectively, our data reveal a functional NPB/NPW system in birds and offer the first proof that NPW can act directly on pituitary to inhibit GH/prolactin secretion in vertebrates.

Goldfish GH-releasing hormone (gGHRH) has been recently identified and shown to stimulate GH release in goldfish. In goldfish, neuroendocrine regulation of GH release is multifactorial and known stimulators include goldfish ghrelin (gGRLN(19)) and salmon gonadotropin-releasing hormone (sGnRH), factors that also enhance LH secretion. To further understand the complex regulation of pituitary hormone release in goldfish, we examined the interactions between gGHRH, gGRLN(19), and sGnRH on GH and LH release from primary cultures of goldfish pituitary cells in perifusion. Treatment with 100 nM gGHRH for 55 mm stimulated GH release. A 5-min pulse of either 1 nM gGRLN(19) or 100 nM sGnRH induced GH release in naive cells, and these were just as effective in cells receiving gGHRH. Interestingly, gGHRH abolished both gGRLN(19)- and sGnRH-induced LH release and reduced basal LH secretion levels. These results suggest that gGHRH does not interfere with sGnRH or gGRLN(19) actions in the goldfish somatotropes and further reveal, for the first time, that GHRH may act as an inhibitor of stimulated and basal LH release by actions at the level of pituitary cells. (C) 2013 Elsevier Inc. All rights reserved.