Dietary wheat bran modulates proliferating cell nuclear antigen-labeling index of the rat colorectum after treatment with 1,2-dimethylhydrazine.
We investigated whether dietary wheat bran (Wb) influences the proliferating cell nuclear antigen (PCNA)-labeling index (LI) of the colorectum of rats after the injection of 1,2-dimethylhydrazine (DMH). Male Wistar/ST rats were divided into four groups and given either a fiber-free diet or diets supplemented with Wb at the expense of the whole diet (5, 10 or 20 g/100 g diet). Then, they were subcutaneously injected with a single dose of DMH (20 mg/kg body weight) or the vehicle. At four weeks after the treatment, frozen sections of the colorectum were immunostained with anti-PCNA antibody (19F4). In the fiber-free group, DMH treatment significantly increased the PCNA-LI of the distal colon and rectum. Among the DMH treatment groups, the PCNA-LI of the distal colon in the Wb 5 g/100 g diet group was significantly lower than that in the fiber-free group. The PCNA-LI of the distal colon tended to increase as the amount of Wb supplemented was increased in the DMH-treated groups except for the fiber-free group. A similar trend was observed for the rectum. In conclusion, the ingestion of Wb diminished the increase in PCNA-LI in rat colorectum induced by DMH injection.
Ishizuka
S
S
Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Kasai
T
T
D019813:1,2-Dimethylhydrazine / Q000494:pharmacology*; D000818:Animals; D001835:Body Weight; D003106:Colon / Q000187:drug effects* / Q000378:metabolism; D004043:Dietary Fiber / Q000494:pharmacology*; D007150:Immunohistochemistry; D008297:Male; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012007:Rectum / Q000187:drug effects* / Q000378:metabolism; D014908:Triticum
D004043:Dietary Fiber; D018809:Proliferating Cell Nuclear Antigen; D019813:1,2-Dimethylhydrazine