Effects of Nutrition on the Radiation Susceptibility (Report 7)

Effects of dietary protein from three kinds of protein sources on the influences of 800 roentgen of whole-body 60Co-γ irradiation against rats were compared using the same criteria as used in Report 6. The three kinds of protein sources were milk casein, soybean oil meal, and mixture of corn flour and soybean oil meal (as protein, 1:3). Dietary protein level of the three test diets in this experiment was 12% each.This experiment showed that the influences of the irradiation were the most significant in rats fed the mixture-protein diet and the influences were the smallest in the animals fed the soybean-protein diet.Concentration of carcass fat in the non-irradiated controls was highest in the animals fed mixture-protein diet, and there was almost no difference in the fat concentration between the both animals fed the casein diet and fed the soybean-protein diet.Concentration of unsaturated fatty acids of carcass fat in the non-irradiated animals fed the mixture-protein diet were the highest, and were the lowest in the animals administered the soybean protein diet. The concentration of unsaturated fatty acids in the animals fed the casein diet was a little higher than that of the animals fed the soybean-protein diet.Although growth of the animals fed the mixture-protein diet was the best among the animals of 3 groups administered the 3 diets during pre-irradiation period, the radiation damages were the most significant in this group.From the results obtained, it is concluded that source of protein is as important factor as dietary protein level in prevention of the radiation damages, and in also concluded that there is difficulties to suspect the radiation susceptibility from the growth of the experimental animals.