Comparative Tumor Initiating Activities of N-Nitrosomethylbenzyl-amine and N-Nitrosodimethylamine in Rat Liver

The tumor initiating activities of nitrosomethylbenzylamine (NMBzA), an esophageal carcinogen, and nitrosodimethylamine(NDMA), a hepatocarcinogen, were compared in rat liver using modifications of the initiation assays. Neither NDMA nor NMBzA significantly inhibited the first wave of DNA synthesis in vivo in the regenerating liver. The results demonstrate that in contrast to NDMA and NDEA nitrosodiethylamine, NMBzA and NMAmA lack tumor initiating activity in the liver.