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Effects of the selective I 1 imidazoline receptor agonist, moxonidine, on gastric secretion and gastric mucosal injury in rats
Author(s) -
Glavin Gary B.,
Smyth Donald D.
Publication year - 1995
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1995.tb13268.x
Subject(s) - moxonidine , imidazoline receptor , agonist , clonidine , gastric acid , chemistry , endocrinology , medicine , receptor , pharmacology , secretion
1 Previous reports of the effects of α 2 ‐adrenoceptor stimulation on gastric secretion are inconsistent because it was not clear whether the compounds were activating α 2 ‐adrenoceptors and/or newly described imidazoline receptors. In the present experiments, the effects of moxonidine, an I 1 ‐imidazoline receptor agonist and antihypertensive agent, on gastric secretion and on experimental gastric mucosal injury were examined. 2 Moxonidine (0.01, 0.1 and 1.0 mg kg −1 , i.p.) potently inhibited basal (non‐stimulated) gastric acid secretion in conscious rats with an ED 50 of 0.04 mg kg −1 . Two hours following administration of the highest dose of moxonidine (1.0 mg kg −1 ), gastric acid output was completely suppressed. Moxonidine also significantly increased intragastric pH, at the two highest doses. 3 The α 2 ‐adrenoceptor agonist, clonidine (0.01, 0.1 and 1.0 mg kg −1 , i.p.) decreased basal acid secretion at the lowest dose (37%) and at the highest dose (46%), while the intermediate dose did not affect gastric acid output. 4 In an ethanol‐induced model of gastric mucosal injury, moxonidine decreased the length of lesions at the lowest and highest doses (0.01 and 1.0 mg kg −1 ) as well as the number of the lesions, at the highest dose (1.0 mg kg −1 ). 5 In pylorus‐ligated rats, moxonidine significantly decreased acid secretion (all doses), total secretory volume (1.0 mg kg −1 ) as well as pepsin output (1.0 mg kg −1 ). 6 In comparison to clonidine, moxonidine appears to be a more potent anti‐secretory and gastric‐protective compound. These data indicate a potential role for imidazoline receptor agonists in the management of gastroduodenal diseases associated with hypertension. The relative contribution of the central and peripheral effects of moxonidine to these gastrointestinal actions remains to be determined.