Galanin and vasopressin response to hyperosmotic stimulation: in vitro study.

摘要: Galanin (Gal)--a neuropeptide present in the nervous system and peripheral tissues--may be involved regulation of hypothalamo-neurohypophysial function. It was shown that centrally injected galanin inhibits osmotically stimulated vasopressin (VP) secretion into blood reduces VP mRNA level supraoptic (SON) paraventricular (PVN) hypothalamic nuclei. The aim study vitro to investigate influence Gal on release from isolated rat hypothalamus (Hth), neurohypophysis (NH) or explants (Hth-NH). effect studied under conditions direct osmotic (i.e., Na⁺-evoked) (series 1) as well nonosmotic K⁺-evoked) 2) stimulation. In series 3, response using neural tissues obtained animals drinking 2 percent NaCl solution for eight days (indirect stimulation). a concentration 10⁻¹⁰ M 10⁻⁸ inhibited basal Hth, NH Hth-NH euhydrated rats complex challenged animals. When previously salt-loaded were incubated K⁺-enriched medium inhibitory completely blocked. may concluded is depending current functional status system.