title: Attenuated apoptosis in H. pylori-colonized gastric mucosa of Mongolian gerbils in comparison with mice.
abstract: Although gastric cancer formation with H. pylori in Mongolian gerbils was recently reported, the same inoculation procedure did not result in cancer formation in other animals such as mice. Disturbed regulation of apoptosis and cell proliferation are known to link the multistep process of carcinogenesis. The present study is designed to examine the level of gastric epithelial cell apoptosis in Mongolian gerbils colonized with the H. pylori (Sydney strain: SS1) in comparison with that in mice. Mice (C57BL/6) and Mongolian gerbils were orally inoculated with SS1 and the stomachs were examined 9 and 18 months later. MPO activity increased persistently in gerbils, but increased transiently in mice. While the levels of DNA fragmentation, caspase-3 activity, and the number of TUNEL-positive cells increased significantly in mice, such parameters were attenuated in gerbils. On the other hand, the number of PCNA-positive cells increased after SS1 inoculation only in Mongolian gerbils, suggesting the enhancement of cell turnover in H. pylori-colonized gerbils. In conclusion, the SS1-induced increase in gastric mucosal apoptosis observed in mice was attenuated significantly in Mongolian gerbils, suggesting the causative role for the higher incidence of gastric carcinogenesis in this animal.
authors.affiliation: Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Masaharu
authors.initials: M
authors.lastname: Miyazawa
authors.forename: Shoichi
authors.initials: S
authors.lastname: Nagahashi
authors.forename: Mikiji
authors.initials: M
authors.lastname: Mori
authors.forename: Koichi
authors.initials: K
authors.lastname: Seto
authors.forename: Akemi
authors.initials: A
authors.lastname: Kai
authors.forename: Masayuki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Soichiro
authors.initials: S
authors.lastname: Miura
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Ishii
mesh_terms: D000818:Animals; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D053938:DNA Fragmentation; D005753:Gastric Mucosa / Q000473:pathology*; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000473:pathology*; D016480:Helicobacter pylori; D020287:In Situ Nick-End Labeling; D051379:Mice; D008810:Mice, Inbred C57BL; D013045:Species Specificity; D013047:Specific Pathogen-Free Organisms; D013274:Stomach Neoplasms / Q000209:etiology
chemical_list: C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases