Effect of low environmental temperature, dinitrophenol, or sodium fluoride on the formation of tumors in mice.

Abstract

The present study was undertaken to determine whether chronic caloric restriction inhibits the formation of tumors through the decreased caloric intake, the associated retardation of body growth, or the reduced total metabolism. Procedures that resulted in retarded body growth despite unchanged or augmented food consumption and total metabolism were investigated: housing mice at low environmental temperature, or feeding them either dinitrophenol or sodium fluoride. Four tumors of the mouse were utilized, but only the mammary carcinoma was investigated with all three experimental procedures. Under the selected conditions, housing the mice at 45°–55° F., or feeding them either 0.25 per cent sodium 2,4 dinitrophenol or 0.09 per cent sodium fluoride, significantly inhibited the formation of spontaneous mammary carcinomas; the feeding of either of the two chemicals significantly inhibited the formation of primary lung adenomas; the two chemicals had little effect upon the formation of induced sarcomas; and dinitrophenol did not appreciably alter the incidence of induced skin tumors. The diverse response of the mammary and lung tumors in comparison with the sarcoma and skin tumor is discussed in relation to experiences with procedures other than those employed in this study. The present data suggest that neither the food consumption (caloric intake) nor the amount or rate of metabolic turnover are consistently related to tumor formation. However, the results with the mammary carcinoma and lung adenoma imply that the inhibition of tumor formation brought about by caloric restriction is associated with the low weight of the animals.