Autoradiography and organ distribution of N-methyl-N-nitro-sobenzylamine in rats

Donryu strain male rats were administered a large amount of N-methyl-N-nitrosobenzylamine directly into the stomach through a tube. Ulcers were found to develop in the portion of the esophagus where esophageal carcinoma is known to develop. Autoradiography of the entire body of rats after an intravenous injection of N-methyl[U-3H]-N-nitrosobenzylamine showed specific incorporation of radioactivity in the esophagus. When N-methyl[U-3H]-N-nitrosobenzyl-amine was injected intravenously, incorporation of radioactivity in the esophagus was higher than in other parts of the alimentary canal, and remained at the same value even after 24 hr. Microautoradiography of rats injected with N-methyl[U-3H]-N-nitrosobenzylamine through the tail vein showed that the silver grains were dominant in the mucous membrane than in the muscle layer in the esophagus. These results suggest that N-methyl-N-nitrosobenzylamine accumulated specifically in the esophagus, resulting in the production of carcinoma.