Inhibition by methionine of pancreatic carcinogenesis in hamsters after initiation with N-nitrosobis(2-oxopropyl) amine.
The modifying effects of dietary L-methionine in the post-initiation phase of pancreatic carcinogenesis were investigated in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). Groups consisting of 20 and 30 animals, respectively, were given BOP subcutaneously, once a week five times at a dose of 10 mg/kg body wt. and then continuously fed diet supplemented with 2% (group 1) or 0% (group 2) methionine (weeks 5-32). After five subcutaneous injections of saline, group 3 animals were similarly fed diet supplemented with 2% methionine for the same period. The incidence of pancreatic ductal adenocarcinomas was significantly lower in group 1 (36.8%, P<0.05) than in group 2 (71.4%). Multiplicity of adenocarcinomas was also significantly lowered (0.52 and 1.28/hamster, P<0.05). Similarly, total numbers of combined adenocarcinomas and dysplastic lesions were significantly decreased in group 1 (2.05, P<0.05) as compared with group 2 (3.67). Methionine enhanced atrophic change of pancreatic acinar cells in hamsters given BOP, indicating that the inhibitory effects on the post-initiation stage of BOP-induced pancreatic carcinogenesis in hamsters could be generally linked to suppression of growth.
Furukawa
F
F
Division of Pathology, National Institute of Health Sciences, 1-18-1 Kamlyoga, Setagaya-ku, Tokyo, Japan.
Nishikawa
A
A
Lee
I S
IS
Son
H Y
HY
Nakamura
H
H
Miyauchi
M
M
Takahashi
M
M
Hirose
M
M
D000273:Adipose Tissue / Q000187:drug effects; D000818:Animals; D001835:Body Weight; D002273:Carcinogens; D006224:Cricetinae; D005260:Female; D008647:Mesocricetus; D008715:Methionine / Q000494:pharmacology*; D009602:Nitrosamines; D010179:Pancreas / Q000187:drug effects; D010190:Pancreatic Neoplasms / Q000139:chemically induced / Q000473:pathology / Q000517:prevention & control*
D002273:Carcinogens; D009602:Nitrosamines; C013622:nitrosobis(2-oxopropyl)amine; D008715:Methionine