Influence of concomitant Miso or NaCl treatment on induction of gastric tumors by N-methyl-N '-nitro-N-nitrosoguanidine in rats

Six-week old male Sprague-Dawley (CD) rats were treated with 100 ppm N-meth yl-N'-nitro-N-nitrosoguanidine (MNNG) for 16 weeks in their drinking water with control, Mise or sodium chloride (NaCl) supplemented diets. All animal s were autopsied 12 months after the beginning of the MNNG treatment. Despi te higher intake of MNNG in the high dose Mise and NaCl groups, the total t umor incidences were decreased compared to middle and lowest values. The gl andular stomach adenocarcinoma incidences in the 10% and 5% Mise groups wer e significantly decreased as compared to those in the 2.2% or 1.1% NaCl gro ups, with the same concentration of NaCl.