Foci of aberrant crypts in the colons of mice and rats exposed to carcinogens associated with foods.

نویسندگان

  • B Tudek
  • R P Bird
  • W R Bruce
چکیده

Aberrant crypt foci can be identified in the colons of rodents treated 3 wk earlier with azoxymethane, a known colon carcinogen. These crypts can easily be visualized in the unsectioned methylene blue-stained colons under light microscopy, where they are distinguished by their increased size, more prominent epithelial cells, and pericryptal space. They occur as single aberrant crypts or as two, three, or four aberrant crypts in a cluster. We compared the reported ability of carcinogens associated with the human diet to induce colon cancer with the measured rate of induction of aberrant crypts in female CF1 mice and Sprague-Dawley rats. The carcinogens used were 1,2-dimethylhydrazine, methyl nitrosourea, N-nitrosodimethylamine, benzo(a)pyrene, aflatoxin B1, 2-amino-6-methyldipyrido[1,2-alpha:3',2'-d]imidazole, 2-amino-3-methylimidazo[4,5-P]quinoline, 2-amino-3,4-dimethylimidazo[4,5-P]quinoline, and 3-amino-1-methyl-5H-pyrido[4,3-b]indole. Graded doses of these compounds were given to the animals by gavage twice with a 4-day interval, and the animals were terminated 3 wk later. All colon carcinogens induced aberrant crypts in a dose-related fashion. N-Nitrosodimethylamine and 3-amino-1-methyl-5H-pyrido[4,3-b]indole, carcinogenic compounds that do not induce colon cancer, did not induce them. The ability of the studied compounds to induce aberrant crypts was species specific; e.g., aflatoxin B1 and 2-amino-3,4-dimethylimidazo[4,5-P]quinoline induce about 20 times more in rats than mice. This relationship was consistent with their reported ability to induce colon cancer in these species. Results of the present study support the use of the aberrant crypt assays to screen colon-specific carcinogens and to study the process of colon carcinogenesis.

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منابع مشابه

Exposed to Carcinogens Associated with Foods Foci of Aberrant Crypts in the Colons of Mice and Rats

Aberrant crypt foci can be identified in the colons of rodents treated 3 wk earlier with azoxymethane, a known colon carcinogen. These crypts can easily be visualized in the unsectioned méthylà ̈ne blue-stained colons under light microscopy, where they are distinguished by their increased size, more prominent epithelial cells, and pericryptal space. They occur as single aberrant crypts or as tw...

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Growth features of aberrant crypt foci that resist modulation by cholic acid.

Previously, we demonstrated that feeding rats a diet containing 0.2% cholic acid (CHA-diet) resulted in the elimination or remodelling of a number of aberrant crypt foci (ACF) in their primal stages (1-3 crypts/focus). The present investigation was conducted to determine if ACF with advanced growth features will respond differently than their primal counterparts to the CHA-diet. Sprague-Dawley ...

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Specificity study to evaluate induction of aberrant crypts in murine colons.

We have previously reported on our findings of aberrant crypts (AC) in the colons of rodents treated with a colon carcinogen. In this report, the specificity of AC formation was assessed by testing a variety of agents for their ability to induce AC in the colons of CF1 and C57BL/6J mice. In addition, the ability of each of the agents to induce nuclear aberrations (NA) was assessed and compared ...

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Aberrant crypt foci and microadenoma as markers for colon cancer.

Foci of aberrant crypts similar to those seen in experimental animals exposed to colon carcinogens have been identified and quantified on the mucosal surface of fixed resections of human colon after methylene blue staining. Many of the foci in humans showed dysplasia on histologic examination and were considered to be microadenoma (MA). These lesions may be precursors for adenomatous polyps and...

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Correspondence between flat aberrant crypt foci and mucin-depleted foci in rodent colon carcinogenesis.

BACKGROUND Flat aberrant crypt foci (flat ACF) and mucin-depleted foci (MDF) are preneoplastic lesions identified in the colon of carcinogen-treated rodents stained with methylene blue (MB) and high iron diamine-alcian blue (HID-AB), respectively. The correspondence between flat ACF and MDF in the same colon of Min mice treated with azoxymethane (AOM) and of F344 rats treated with 1,2-dimethylh...

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عنوان ژورنال:
  • Cancer research

دوره 49 5  شماره 

صفحات  -

تاریخ انتشار 1989