Cocarcinogenic action of aspirin on gastric tumors induced by N-nitroso-N-methylnitroguanidine in rats.
Albino rats (noninbred) were divided into 4 groups: 1) 56 control rats, 2) 40 rats fed 1 ml aspirin suspension (40 mg/ml) twice a week, 3) 20 rats given N-nitroso-N-methylnitroguanidine (MNNG) solution (250 micrograms/ml) to drink ad libitum, and 4) 40 rats given both aspirin and MNNG. In 18 months, there were no gastrointestinal tumors in groups 1 and 2, 8 cases of gastric tumors in group 3, and 37 cases of gastric tumors in group 4. Adenocarcinomas of the glandular stomach were found in 21 of 40 rats in group 4 but in only 4 of the 20 rats in group 3; the difference in incidence was significant. Histologic and electron microscopic examination of the epidermoid carcinomas and adenocarcinomas in group 4 showed no difference from such tumors induced by MNNG only. Hyperplasia of the forestomach mucosa and hyperplasia of the pyloric gland region of the glandular stomach in group 4 were more severe.
D000230:Adenocarcinoma / Q000139:chemically induced; D000818:Animals; D001241:Aspirin / Q000633:toxicity*; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced; D003043:Cocarcinogenesis; D005260:Female; D006801:Humans; D008297:Male; D008769:Methylnitronitrosoguanidine; D009374:Neoplasms, Experimental / Q000139:chemically induced; D010212:Papilloma / Q000139:chemically induced; D011336:Probability; D051381:Rats; D013274:Stomach Neoplasms / Q000139:chemically induced*
D008769:Methylnitronitrosoguanidine; D001241:Aspirin