Tumor induction by azoxymethane (AOM) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in F344 rat gastric mucosa featuring intestinal metaplasia caused by X-irradiation.
Male F344 5-week-old rats were X-irradiated, and 16 weeks after the first dose, azoxymethane (AOM) was injected or 2-amino-1 -methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) was given by intragastric intubation. Tumors in the pylorus of the glandular stomach were observed in 4 out of the 29 animals receiving X-rays + AOM and in 4 out of the 25 animals receiving X-rays + PhIP, 12 months after administration. No such lesions were found in the chemical or X-ray alone groups. Intestinal metaplasia and some induced tumors were positive for CDX2. It was concluded that the presence of intestinal metaplasia may increase sensitivity to the induction of gastric tumors by colon carcinogens.
Kashiwabara
S
S
Dept. of Experimental Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, Japan.
Kashimoto
N
N
Uesaka
T
T
Wakabayashi
K
K
Kamiya
K
K
Watanabe
H
H
D000818:Animals; D001397:Azoxymethane; D001835:Body Weight; D002273:Carcinogens; D018279:Carcinoma, Signet Ring Cell / Q000139:chemically induced / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism; D005753:Gastric Mucosa / Q000473:pathology*; D007093:Imidazoles; D007150:Immunohistochemistry; D007422:Intestines / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D008297:Male; D008679:Metaplasia; D009153:Mutagens; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D009929:Organ Size; D051381:Rats; D011916:Rats, Inbred F344; D013274:Stomach Neoplasms / Q000139:chemically induced*; D013997:Time Factors; D014965:X-Rays
D002273:Carcinogens; D007093:Imidazoles; D009153:Mutagens; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine; D001397:Azoxymethane