Increased susceptibility of adult rats to azoxymethane-induced aberrant crypt foci.
Cancer Lett
; 161(2): 185-93, 2000 Dec 20.
Article
em En
| MEDLINE
| ID: mdl-11090968
ABSTRACT
The purpose of this study was to compare azoxymethane-induced aberrant crypt foci development in the colons of young and adult rats. Young (4 weeks of age) and adult (50 weeks of age) Sprague-Dawley rats were treated with two weekly injections of azoxymethane or saline. Rats were killed either 6 or 14 weeks following the first injection, and the number, size and location of aberrant crypt foci were determined. At both the 6- and 14-week time points, the number of aberrant crypt foci in older rats was significantly greater than in young rats (P<0.01). A higher percentage of aberrant crypt foci were found in the region from the mid-colon to the cecum in older rats as compared to young rats. Colonic cell proliferation was evaluated using bromodeoxyuridine immunohistochemistry. Colonic cell proliferation indices in the rectal, mid-colon and cecal regions of young and older rats were similar in young compared to adult rats. Ten large ACF from each group were screened for mutations in the beta-catenin gene (Ctnnb1) by PCR single strand conformation polymorphism. No mutations were detected. These results demonstrate that older female rats are more susceptible to the induction of aberrant crypt foci by azoxymethane than young female rats. Differences in colonic cell proliferation or beta-catenin mutations in these two age groups do not appear to be responsible for differences in aberrant crypt foci development.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Lesões Pré-Cancerosas
/
Azoximetano
/
Transativadores
/
Doenças do Colo
Limite:
Animals
Idioma:
En
Revista:
Cancer Lett
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos