J K Ko1, C H Cho. 1. Department of Pharmacology, Faculty of Medicine, The University of Hong Kong, China.
Abstract
OBJECTIVE: The correlation between mucosal generation of nitric oxide (NO) and prostaglandin E2 (PGE2) in gastric adaptive cytoprotection was investigated. MATERIALS AND TREATMENT: Male Sprague-Dawley rats were pretreated with either N(w)-nitro-L-arginine methyl ester (L-NAME, 12.5 mg/kg i.v.) or indomethacin (5 mg/kg s.c.). Following that, mild irritant 20% ethanol was administered, 15 min prior to 100% ethanol challenge. METHODS: Macroscopic gastric mucosal damage, NO synthase activity, mucosal PGE2 and leukotriene C4 (LTC4) levels were measured. RESULTS: Administration of L-NAME and indomethacin significantly reduced the protective action of 20% ethanol against 100% ethanol-induced gastric mucosal damage. Besides, mucosal activity of constitutive NO (cNO) synthase, but not of the inducible isozyme (iNO synthase), was elevated following 20% ethanol treatment. This was accompanied by a reduction in mucosal leukotriene C4 level. Indomethacin significantly inhibited mucosal PGE2 biosynthesis but increased cNO synthase activity. Nevertheless, L-NAME reduced both cNO and iNO formation and prevented the increase in cNO formation caused by 20% ethanol, while enhancing mucosal PGE2 production. Combined L-NAME and indomethacin treatment markedly potentiated ethanol-induced mucosal damage, and completely prevented the increase in cNO or PGE2 biosynthesis when either compound was given alone. CONCLUSIONS: These findings suggest a co-regulatory relationship between mucosal NO and PG in the gastric defense system, which will be released after activation by the mild irritants to induce cytoprotection.
OBJECTIVE: The correlation between mucosal generation of nitric oxide (NO) and prostaglandin E2 (PGE2) in gastric adaptive cytoprotection was investigated. MATERIALS AND TREATMENT: Male Sprague-Dawley rats were pretreated with either N(w)-nitro-L-arginine methyl ester (L-NAME, 12.5 mg/kg i.v.) or indomethacin (5 mg/kg s.c.). Following that, mild irritant 20% ethanol was administered, 15 min prior to 100% ethanol challenge. METHODS: Macroscopic gastric mucosal damage, NO synthase activity, mucosal PGE2 and leukotriene C4 (LTC4) levels were measured. RESULTS: Administration of L-NAME and indomethacin significantly reduced the protective action of 20% ethanol against 100% ethanol-induced gastric mucosal damage. Besides, mucosal activity of constitutive NO (cNO) synthase, but not of the inducible isozyme (iNO synthase), was elevated following 20% ethanol treatment. This was accompanied by a reduction in mucosal leukotriene C4 level. Indomethacin significantly inhibited mucosal PGE2 biosynthesis but increased cNO synthase activity. Nevertheless, L-NAME reduced both cNO and iNO formation and prevented the increase in cNO formation caused by 20% ethanol, while enhancing mucosal PGE2 production. Combined L-NAME and indomethacin treatment markedly potentiated ethanol-induced mucosal damage, and completely prevented the increase in cNO or PGE2 biosynthesis when either compound was given alone. CONCLUSIONS: These findings suggest a co-regulatory relationship between mucosal NO and PG in the gastric defense system, which will be released after activation by the mild irritants to induce cytoprotection.
Authors: V Sibilia; F Pagani; G Rindi; N Lattuada; D Rapetti; V De Luca; N Campanini; I Bulgarelli; V Locatelli; F Guidobono; C Netti Journal: Br J Pharmacol Date: 2008-04-14 Impact factor: 8.739
Authors: Heyam Mohamed Ali Sidahmed; Ainnul Hamidah Syahadah Azizan; Syam Mohan; Mahmood Ameen Abdulla; Siddig Ibrahim Abdelwahab; Manal Mohamed Elhassan Taha; A Hamid A Hadi; Kamal Aziz Ketuly; Najihah Mohd Hashim; Mun Fai Loke; Jamuna Vadivelu Journal: BMC Complement Altern Med Date: 2013-07-19 Impact factor: 3.659