Influence of Dinitrokresol on the Development of Tar Tumors in Mice

Abstract

In previous papers (1 and 2) I have shown that it is possible by dietetic measures to influence the time of the occurrence of tar tumors in mice. Some of these findings are in complete agreement with the results obtained by other students of this question. Most of the dietetic changes resulted in an earlier occurrence of tumors in those animals which, in accordance with the individual variation of the response, were expected to react comparatively late. Animals ordinarily giving an early response seem not to have been influenced. When these observations are graphically expressed (Graph 1) the curves of the control and experimental groups are seen to start from the same point, but that for the experimental animals shows a more rapid rise. This holds good in experiments with butter and fresh liver. In my hands liver-fed animals have not shown an earlier reaction with permanent benign tumors. The earlier warts observed by Maisin and Francois and by Watson have occurred in my material, but they were of a transitory type and I have designated them as ephemeral warts. If these ephemeral warts are disregarded, the ordinary correlation between benign and malignant tumors is preserved, the curve of the malignant warts having the same point of origin in both experimental and control material, with a more rapid rise for the former.