title: Substance P induces gastric mucosal protection at supraspinal level via increasing the level of endomorphin-2 in rats.
abstract: The aim of the present study was to analyze the potential role of substance P (SP) in gastric mucosal defense and to clarify the receptors and mechanisms that may be involved in it. Gastric ulceration was induced by oral administration of acidified ethanol in male Wistar rats. Mucosal levels of calcitonin gene-related peptide (CGRP) and somatostatin were determined by radioimmunoassay. For analysis of gastric motor activity the rubber balloon method was used. We found that central (intracerebroventricular) injection of SP (9.3-74 pmol) dose-dependently inhibited the formation of ethanol-induced ulcers, while intravenously injected SP (0.37-7.4 nmol/kg) had no effect. The mucosal protective effect of SP was inhibited by pretreatment with neurokinin 1-, neurokinin 2-, neurokinin 3- and μ-opioid receptor antagonists, while δ- and κ-opioid receptor antagonists had no effect. Endomorphin-2 antiserum also antagonized the SP-induced mucosal protection. In the gastroprotective dose range SP failed to influence the gastric motor activity. Inhibition of muscarinic cholinergic receptors, or the synthesis of nitric oxide or prostaglandins significantly reduced the effect of SP. In addition, centrally injected SP reversed the ethanol-induced reduction of gastric mucosal CGRP content. It can be concluded, that SP may induce gastric mucosal protection initiated centrally. Its protective effect is likely to be mediated by endomorphin-2, and vagal nerve may convey the centrally initiated protection to the periphery, where both prostaglandins, nitric oxide and CGRP are involved in mediating this effect.
authors: Department of Pharmaceutical Sciences - Pharmacology Section, University of Catania, Viale A. Doria 6, 95125 Catania, Italy.
authors: Serena B
authors: SB
authors: Brancati
authors: Zoltán S
authors: ZS
authors: Zádori
authors: József
authors: J
authors: Németh
authors: Klára
authors: K
authors: Gyires
mesh_terms: D000438:Alcohols / Q000633:toxicity; D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000096:biosynthesis; D004195:Disease Models, Animal; D000431:Ethanol / Q000633:toxicity; D005753:Gastric Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007276:Injections, Intraventricular; D008297:Male; D018377:Neurotransmitter Agents / Q000008:administration & dosage / Q000378:metabolism*; D009842:Oligopeptides / Q000096:biosynthesis*; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D013373:Substance P / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D000438:Alcohols; D018377:Neurotransmitter Agents; D009842:Oligopeptides; D013373:Substance P; D000431:Ethanol; C105294:endomorphin 2; D015740:Calcitonin Gene-Related Peptide