title: Effect of duodenogastric reflux on N-methyl-N'-nitro-N-nitrosoguanidine-induced glandular stomach tumorigenesis in Helicobacter pylori-infected Mongolian gerbils.
abstract: Both Helicobacter pylori (Hp) and bile acids are gastric carcinogens. An experimental model of duodenogastric reflux in Mongolian gerbils was developed and was used to study the effects of Hp infection and duodenogastric reflux on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced glandular stomach tumorigenesis independently and synergistically. Male Mongolian gerbils underwent both inoculation with Hp, and had duodenogastric reflux (DR) induced, or neither, followed by MNNG administration. Animals were sacrificed at week 40, and histopathological examination of their excised stomachs and serological investigation were performed. Glandular stomach adenocarcinomas were observed in animals that underwent Hp inoculation and/or induction of DR after MNNG administration, and glandular stomach adenomas were found in animals inoculated with Hp after MNNG administration. The incidence of glandular stomach tumors was significantly higher in animals inoculated with Hp after MNNG administration and in animals undergoing combined Hp inoculation, DR induction and MNNG administration than in animals only administered MNNG. These findings indicate that Hp infection has a stronger tumorigenic effect than the exposure to duodenal contents, and duodenal contents may attenuate the effect of Hp on glandular stomach tumorigenesis.
authors.affiliation: Department of Gastroenterological Surgery, Osaka City University, Graduate School of Medicine, Abeno-ku, Osaka 545-8585, Japan. yoshy@msic.med.osaka-cu.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Harushi
authors.initials: H
authors.lastname: Osugi
authors.forename: Keiichirou
authors.initials: K
authors.lastname: Morimura
authors.forename: Masashi
authors.initials: M
authors.lastname: Takemura
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Ueno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kaneko
authors.forename: Shoji
authors.initials: S
authors.lastname: Fukushima
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kinoshita
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000818:Animals; D003849:Deoxyguanosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004383:Duodenogastric Reflux / Q000150:complications* / Q000382:microbiology; D005766:Gastrointestinal Contents / Q000737:chemistry; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000150:complications*; D007249:Inflammation / Q000150:complications / Q000382:microbiology / Q000473:pathology; D008297:Male; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology*; D008986:Mongolia; D009375:Neoplasms, Glandular and Epithelial / Q000139:chemically induced* / Q000150:complications / Q000382:microbiology* / Q000473:pathology; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000150:complications / Q000382:microbiology* / Q000473:pathology
chemical_list: D008769:Methylnitronitrosoguanidine; D000080242:8-Hydroxy-2'-Deoxyguanosine; D003849:Deoxyguanosine