title: Enhanced effect of gastrin on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.
abstract: This study deals with the effects of gastrin on the incidence of gastric tumors in rats induced by N-methyl-N'-nitro-N-nitrosoguanidine. Inbred Basel-Wistar rats received N-methyl-N'-nitro-N-nitrosoguanidine in drinking water (50 micrograms/ml for 32 weeks) in order to produce gastric carcinoids. A treatment with s.c. injection of pentagastrin (300 micrograms/kg, once daily for 4 weeks) was started at the beginning of N-methyl-N'-nitro-N-nitrosoguanidine treatment simultaneously, on the 4th, 8th, 16th, and 32nd week after start of N-methyl-N'-nitro-N-nitrosoguanidine treatment, respectively. At autopsy, from the 55th to 60th week after start of the experiment, only in the eighth-week group of gastrin-treated rats was the incidence of gastric carcinoid significantly higher than in the gastrin-untreated group of rats receiving N-methyl-N'-nitro-N-nitrosoguanidine alone. The incidence of adenocarcinoma in the glandular stomach also was high only in the fourth-week group of gastrin-treated rats. However, these effects could not be seen in other gastrin-treated or untreated groups of rats. The data suggest that gastrin treatment in the early stage of rat stomach carcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine is effective in increasing the development of gastric tumors.
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced; D000818:Animals; D002276:Carcinoid Tumor / Q000139:chemically induced; D004032:Diet; D004357:Drug Synergism; D005260:Female; D007414:Intestinal Neoplasms / Q000139:chemically induced / Q000473:pathology; D008297:Male; D008769:Methylnitronitrosoguanidine; D010418:Pentagastrin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000473:pathology; D013997:Time Factors
chemical_list: D008769:Methylnitronitrosoguanidine; D010418:Pentagastrin