Enhancement by peptide histidine isoleucine of experimental carcinogenesis in the colon of rats induced by azoxymethane.
The effects of peptide histidine isoleucine (PHI) on the incidence and histology of colon tumors induced by azoxymethane (AOM), and on the labeling index of colon mucosa were investigated in Wistar rats. Rats received weekly s.c. injections of 7.4 mg/kg body weight of AOM for 10 weeks, and of 1.0 or 4.0 nmol/kg body weight of PHI until the end of the experiment in week 35. Administration of PHI at the higher, but not the lower dosage, significantly increased the incidence of colon tumors. PHI had no influence on the histology of colon tumors or adenocarcinomas. It also caused significant increase in the labeling index of colon epithelial cells. These findings indicate that PHI enhances colon carcinogenesis, and that its effect may be related to increasing proliferation of colon epithelial cells.
Iishi
H
H
Department of Gastrointestinal Oncology, Center for Adult Diseases, Osaka, Japan.
Tatsuta
M
M
Baba
M
M
Iseki
K
K
Uehara
H
H
Nakaizumi
A
A
D000230:Adenocarcinoma / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D001397:Azoxymethane; D001835:Body Weight / Q000187:drug effects; D003106:Colon / Q000187:drug effects; D003110:Colonic Neoplasms / Q000097:blood / Q000139:chemically induced* / Q000473:pathology; D004357:Drug Synergism; D005755:Gastrins / Q000097:blood; D007413:Intestinal Mucosa / Q000187:drug effects; D010451:Peptide PHI / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D005755:Gastrins; D010451:Peptide PHI; D001397:Azoxymethane