title: Colon tissue implanted into the glandular stomach in rats lack susceptibility to N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) carcinogenesis.
abstract: The present study was undertaken to determine the response of colon mucosa implanted into the fundus of stomach in 6-week old male F344 rats to oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Samples of colonic tissue about 8 mm in diameter were obtained from various colon sites and surgically implanted into the anterior wall of the fundus by isografting. MNNG was chronically administered at a concentration of 100 mg/l in the drinking water for 16 weeks starting 4 weeks after the operation and the grafted colon mucosa was examined at 12 months after the operation. Control rats received a sham-operation and the same amount of MNNG. In the MNNG administered groups, only one adenoma containing Paneth cells was noted in the implanted colon tissue whereas over 40% incidence of gastric tumors was observed in the pyloric mucosa. In the operated rats not given MNNG no gastric tumors were observed in either the grafted site or the pylorus.
authors: HIROSHIMA UNIV,DEPT ENVIRONM & MUTAT,RES INST RADIAT BIOL & MED,MINAMI KU,HIROSHIMA 734,JAPAN. HIROSHIMA UNIV,DEPT CANC RES,RES INST RADIAT BIOL & MED,HIROSHIMA 734,JAPAN.
authors: Y
authors: Y
authors: Nakagawa
authors: Y
authors: Y
authors: Ando
authors: N
authors: N
authors: Fujimoto
authors: Y
authors: Y
authors: Masaoka
authors: M
authors: M
authors: Tanizaki
authors: S
authors: S
authors: Syoji
authors: O
authors: O
authors: Katoh
authors: H
authors: H
authors: Watanabe