title: H2-receptor antagonists protect against aspirin-induced gastric lesions in the rat.
abstract: Gastric mucosal lesions were produced in rats by dosing orally with aspirin, 300 mg/kg. Predosing orally with either ranitidine or cimetidine inhibited this lesion formation; the respective ED50 values were 0.8 and 3.9 mg/kg p.o. Oral ranitidine also inhibited lesion formation in the presence of exogenous 160 mM HCl, with an ED50 value of 23.2 mg/kg p.o. Subcutaneous injection of ranitidine inhibited the formation of aspirin-induced lesions both in the presence and in the absence of excess HCl. The ED50 values were respectively 3.4 and 0.9 mg/kg s.c. Mepyramine maleate (5 mg/kg p.o.) alone had no effect on gastric lesion formation, and did not influence the level of inhibition produced by ranitidine either in the absence of presence of exogenous acid.
mesh_terms: D000818:Animals; D001241:Aspirin / Q000037:antagonists & inhibitors*; D002927:Cimetidine / Q000494:pharmacology; D005260:Female; D005663:Furans / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D011738:Pyrilamine / Q000494:pharmacology; D011899:Ranitidine; D051381:Rats; D013276:Stomach Ulcer / Q000139:chemically induced / Q000517:prevention & control*
chemical_list: D005663:Furans; D006635:Histamine H2 Antagonists; D002927:Cimetidine; D011899:Ranitidine; D011738:Pyrilamine; D001241:Aspirin