Enhancing effects of N-ethyl-N'-nitro-N-nitrosoguanidine and sodium taurocholate on development of pepsinogen 1 decreased pyloric glands in rats initiated with N-methyl-N'-nitro-N-nitrosoguanidine.
Sequential quantitative analyses were made of pepsinogen 1 (Pg 1) decreased pyloric glands after treating male WKY rats first with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and then with N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) as a second gastric carcinogen or sodium taurocholate (Na-TC) as a gastric promoter. Animals received a single dose of MNNG (160 mg/kg body weight) by gastric intubation followed two weeks later by either ENNG in drinking water (100 micrograms/ml) (group 1), basal diet containing 0.25% Na-TC (group 2), or basal diet and tap water (group 3), from weeks 3 to 24. Animals were sacrificed at weeks 8, 12, 16, 20 and 24. Sections of the pyloric mucosa were investigated for Pg 1 immunostaining. In comparison with group 3, induction of Pg 1 decreased pyloric glands was significantly enhanced by ENNG from week 8 and by Na-TC from week 16. The former exerted a significantly stronger effect at each time point. The results suggest that Pg 1 decreased pyloric glands represent a good marker for early detection of gastric carcinogens and promoters in in vivo test systems.
D000818:Animals; D002273:Carcinogens; D005753:Gastric Mucosa / Q000201:enzymology; D007158:Immunologic Techniques; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000031:analogs & derivatives; D010435:Pepsinogens / Q000378:metabolism*; D011230:Precancerous Conditions / Q000139:chemically induced / Q000201:enzymology*; D051381:Rats; D013274:Stomach Neoplasms / Q000139:chemically induced / Q000201:enzymology*; D013656:Taurocholic Acid
D002273:Carcinogens; D007527:Isoenzymes; D010435:Pepsinogens; D008769:Methylnitronitrosoguanidine; C013525:ENNG; D013656:Taurocholic Acid