title: Substance P stimulates Growth Hormone (GH) and GH-Releasing Hormone (GHRH) secretions through tachykinin NK2 receptors in sheep.
abstract: Substance P is ubiquitous undecapeptide belonging to the tachykinins family. It has been found in the hypothalamus and is involved in the hypothalamo-hypophysial axis in several mammals, including human. Previous studies have shown that substance P increases GH secretions in rats and human. In this study, we have shown that intravenously infused substance P in sheep caused an increased level of Growth Hormone (GH) and GH-Releasing Hormone (GHRH), and decreased Somatotropin Release Inhibiting Hormone (SRIH) secretions. GH was obtained from peripheral blood. GHRH and SRIH were directly collected from hypophysial portal blood, using a trans-nasal surgery technique in a vigil sheep that allowed accessing to hypothalamo-hypophysial portal vessels. Hormones assays were performed by radioimmunoassay (RIA). Moreover, we showed that substance P-induced GH and GHRH secretion appears to be mediated by NK2 tachykinin receptors, since it is specifically blocked by a non peptidic tachykinin NK2 receptor antagonist (SR48968, Sanofi, Montpellier, France) whereas a non peptidic tachykinin NK1 antagonist (SR140333, Sanofi, Montpellier, France) failed to modify GH and GHRH hormones secretions.
authors.affiliation: University of Aix-Marseille and Institut National de la Santé Et de la Recherche Médicale (INSERM) U 297, Laboratory of Experimental Neuroendocrinology, Boulevard P. Dramard, 13916 Marseille cedex 20, France. guylemamy@yahoo.fr
authors.forename: Guy-Joseph
authors.initials: GJ
authors.lastname: Lemamy
authors.forename: Viviane
authors.initials: V
authors.lastname: Guillaume
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Ndéboko
authors.forename: Justine
authors.initials: J
authors.lastname: Mouecoucou
authors.forename: Charles
authors.initials: C
authors.lastname: Oliver
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D013007:Growth Hormone-Releasing Hormone / Q000097:blood / Q000378:metabolism*; D008297:Male; D010880:Piperidines / Q000494:pharmacology; D011812:Quinuclidines / Q000494:pharmacology; D018041:Receptors, Neurokinin-2 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012756:Sheep; D013004:Somatostatin / Q000097:blood / Q000378:metabolism; D013373:Substance P / Q000502:physiology*
chemical_list: D001549:Benzamides; D010880:Piperidines; D011812:Quinuclidines; D018041:Receptors, Neurokinin-2; C085215:SR 140333; D013373:Substance P; D013004:Somatostatin; C073839:SR 48968; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone