Premium
Enhanced induction of colon carcinogenesis by azoxymethane in wistar rats fed a low‐protein diet
Author(s) -
Tatsuta Masaharu,
Iishi Hiroyasu,
Baba Miyako,
Taniguchi Haruo
Publication year - 1992
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910500122
Subject(s) - azoxymethane , casein , histology , medicine , norepinephrine , endocrinology , colorectal cancer , low protein diet , carcinogen , carcinogenesis , intestinal mucosa , biology , biochemistry , cancer , dopamine
The effects of ad libitum feeding of synthetic, low‐protein diets on the incidence, number and histology of colon tumors induced by azoxymethane (AOM), on the norepinephrine concentration in the colon wall tissue and on the labelling index of colon mucosa were investigated in Wistar rats. Rats received 10 weekly injections of 7.4 mg/kg body weight of AOM and were given synthetic diets of equal calory content containing 25% casein (normal‐protein diet), 10% casein (low‐protein diet) or 5% casein (very‐low‐protein diet). Administration of the low‐ and very‐low‐protein diets resulted in significant increases in the incidence and number of colon tumors at week 30. However, it did not affect the histology of the colon tumors. The low‐ and very‐low‐protein diets also resulted in significant increases in norepinephrine concentration in the proximal and distal portions of the colon wall and in the labelling indices of both parts of the colon mucosa. Our findings indicate that low‐ and very‐low‐protein diets enhance colon carcinogenesis and that this may be related to their effects in increasing the norepinephrine level in the colon wall and in stimulating proliferation of colon epithelial cells.