Gastric tumorigenicity of 1,2-dimethylhydrazine on the background of gastric intestinal metaplasia induced by X-irradiation in CD (SD) rats.
Five-week-old male CD (SD) rats were X-irradiated with a total of 20 Gy in 2 equal fractions with a 3-day interval. After the second irradiation, rats were fed normal diet supplemented with 1% sodium chloride, which is known to increase intestinal metaplasia. 1,2-Dimethylhydrazine (DMH) solution was injected i.m. into the back musculature at a dose of 20 mg/kg body weight weekly for 10 weeks, beginning 20 weeks after the final irradiation. Twelve months after the initial carcinogen treatment, gastric tumors in the glandular stomach were observed in 2 (3 lesions) of 30 animals in the X-irradiated and DMH-treated group fed diet supplemented with 1% sodium chloride. No gastric tumors were observed in the group which excluded X-irradiation from the experimental protocol.
Ando
Y
Y
Department of Cancer Research, Hiroshima University, Japan.
Watanabe
H
H
Tatematsu
M
M
Hirano
K
K
Furihata
C
C
Fujimoto
N
N
Toge
T
T
Ito
A
A
D019813:1,2-Dimethylhydrazine; D000818:Animals; D002273:Carcinogens; D004127:Dimethylhydrazines; D005753:Gastric Mucosa / Q000187:drug effects / Q000473:pathology*; D007414:Intestinal Neoplasms / Q000139:chemically induced; D007420:Intestine, Large / Q000473:pathology; D008297:Male; D008679:Metaplasia / Q000150:complications* / Q000209:etiology; D051381:Rats; D013270:Stomach / Q000473:pathology / Q000528:radiation effects; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000737:chemistry; D014965:X-Rays
D002273:Carcinogens; D004127:Dimethylhydrazines; D019813:1,2-Dimethylhydrazine