Modulation of N-Nitrosodiethylamine Induced Hamster Lung Tumors by Nitrogen Dioxide

Abstract

The objective of the study was to examine whether continuous exposure to NO₂ would modify the development of chemically induced lung tumors. Male Syrian golden hamsters were treated, twice a week, with sc injections of N-nitrosodiethylamine (DEN) while being exposed for 23 h/d, 7 dlwk to 15 ppm of NO₂. Animals were sacrificed 4 mo and 6–8 mo after the beginning of the experiment. No lung tumors were found in hamsters treated with DEN and exposed to NO₂ whereas 26% of the animals treated with DEN alone had peripheral lung tumors after 6–8 mo. The development of tracheal tumors was delayed by exposure to the pollutant. The results of the experiment do not allow implication of NO₂ as a possible enhancer of respiratory tract tumors in hamsters.