Changes in the number and apoptosis of epithelial cells in the colorectum of wheat bran-fed rats soon after administering 1,2-dimethylhydrazine.
We investigated the effect of dietary wheat bran (Wb) on colonic tumorigenesis soon after a single administration of 1,2-dimethylhydrazine (DMH). Rats that had been fed on either a fiber-free diet or a 20% Wb diet were injected with 1,2-dimethylhydrazine (20 mg/kg body weight). At 6h, 12h, 1d, 3d, or 7d after the injection, the colorectum was excised for histological analyses. The number of crypt cells more rapidly recovered in the 20% Wb group than in the fiber-free group after its temporary reduction by injection of DMH. At 6h after the DMH treatment, the apoptotic cells were significantly greater in number in the fiber-free group than in the 20% Wb group. In contrast, those in distal colon were significantly fewer in the fiber-free group than in the 20% Wb group at 7d after the treatment. These results suggest that the ingestion of Wb affected the turnover of colonic epithelial cells and would thereby bring about a protective effect against DMH-induced tumorigenesis.
Ishizuka
S
S
Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Sonoyama
K
K
Kasai
T
T
D019813:1,2-Dimethylhydrazine / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002273:Carcinogens / Q000633:toxicity*; D002452:Cell Count; D003106:Colon / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D004032:Diet; D004043:Dietary Fiber / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012007:Rectum / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000187:drug effects
D002273:Carcinogens; D004043:Dietary Fiber; D005227:Fatty Acids; D018809:Proliferating Cell Nuclear Antigen; D019813:1,2-Dimethylhydrazine