INDOMETHACIN TREATMENT OF RATS WITH DIMETHYLHYDRAZINE-INDUCED INTESTINAL TUMORS

Abstract

Intestinal tumors were induced in male Sprague-Dawley rats following the administration of 5 weekly doses of 1,2-dimethylhydrazine (DMH) by gavage. At intervals thereafter, groups of rats were given indomethacin (IND) in the drinking water. In 3 trials, the incidence of rats with tumors was significantly reduced by 40% below the control rats which did not receive IND; there was no significant difference in body weights. In those IND-treated rats which developed tumors, the tumors were generally smaller in numbers and sizes compared to the control rats. A group of DMH-treated rats was treated with crude IND by gavage; the differences between them and untreated control rats were not significant. The treatment probably was directed at the tumors and not at the DMH which induced them.