Influence of dietary protein on gastric tumorigenesis by N-methyl-N ' -nitro-N-nitrosoguanidine in rats

In our preliminary report, the genesis and development of NG-induced gastric tumor in rats maintained on a 50 percent casein diet throughout the experiment were enhanced more significantly than those fed on a low protein diet. An attempt was made to determine at what phase of the neoplastic process casein might be considered to have its effect.Alterations in the dietary protein content were performed on the 20th week after the initiation of the experiment. This caused a slight increase in the genesis and tumor growth of the glandular stomach by giving a higher protein diet but did not show a significant difference.Urine volume and urea nitrogen excretion of rats fed on 50 percent casein diet manifested a significant increment compared with those of rats fed on 20 and 8 percent casein diets. Thus, the uptake of a high protein diet appears to influence the metabolism of rats receiving NG, but the details remain to be elucidated.