Nitric oxide inhibition intensifies cold-restraint induced gastric ulcers in rats.
Treatment 20 min beforehand with an inhibitor of nitric oxide (NO) synthesis NW-nitro-1-arginine methyl ester (L-NAME) (12.5, 25, 50 or 100 mg/kg, s.c.), dose-dependently intensified gastric glandular mucosal ulceration produced by cold-restraint stress. Hexamethonium (20 mg/kg) or atropine (1 mg/kg) pretreatment s.c. 20 min before stress strongly antagonised stress-evoked ulceration, as well as the ulcer-potentiating effects of L-NAME when either cholinoceptor antagonist was given concurrently with the NO inhibitor. Stress-induced mast cell degranulation was not worsened by L-NAME pretreatment. The findings suggest that NO could confer partial protection against stress-induced gastric ulcer formation; its activity is triggered off by the ulcerogenic mechanism of stress.
Ogle
C W
CW
Department of Pharmacology, Faculty of Medicine, University of Hong Kong.
Qiu
B S
BS
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D003080:Cold Temperature; D005260:Female; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008407:Mast Cells / Q000502:physiology; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013276:Stomach Ulcer / Q000209:etiology*; D013312:Stress, Physiological / Q000150:complications*
D006584:Hexamethonium Compounds; D009569:Nitric Oxide; D018738:Hexamethonium; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester