Effects of Food Irradiated with X-rays upon Mice

Abstract

IN the first era of radiotherapy the theory prevailed that the action of X-rays was confined to the irradiated area; in other words, it was regarded as a local process. Gradually, observations accumulated which furnished positive proof that X-rays also exert a general action upon the irradiated individual, particularly upon his blood. Only few facts may be cited. The hemoglobin and blood sugar show certain quantitative changes after irradiation. The sedimentation time of the red blood corpuscles is prolonged. The leukocytes are affected and destroyed. Often the blood pressure is lowered. The quantity of sodium chloride in blood serums is diminished. The acidosis of blood serum after irradiation soon subsides and gives place to alkalosis; the amount of creatinin and fat in serum increases; coagulation time of blood is shortened; increased diuresis is produced; more sodium chloride is excreted by the kidneys; the metabolism is lowered. The activity of invisible rays is not limited to living tissues. Experiments of Steen-bock and Black (1) and at the same time those of Hess (2), have demonstrated that the exposure of some foods to ultra-violet radiation endows those substances with antirachitic properties, not previously possessed by them. Thus the power of cod liver oil to prevent rickets can be given to almond or olive oil by irradiation with ultra-violet rays, emitted by a mercury vapor lamp. Other vegetable oils and leafy vegetables may be influenced in a similar manner. Only recently has the significance of the invisible radiations for the welfare of human beings begun to be appreciated. The striking experience with regard to the effect of ultraviolet rays has led to further investigations of the action of invisible rays. Ludwig and Hopf (3) undertook a series of experiments to study the properties of food irradiated with X-rays. Bread and carrots were exposed to the action of roentgen rays and then were used as food for young white rats. Shortly after the experiments were started the rats ceased to increase in weight. Very soon a rapid loss of weight could be noticed in every animal, followed by death fifteen to thirty days later. At the end of the twelfth week from the beginning of the experiments, every rat was dead; forty-seven out of fifty control animals were still alive. A diminished appetite, toilsome movements, and tenderness of bones to pressure could be observed in animals fed with irradiated food. The autopsies revealed a fatty degeneration of myocardium and liver, hyperemia of spleen, and signs of rickets in the bones. In regard to the technic of irradiations the authors do not make exact statements. They merely mention that hard rays, 220 K.W., and a filter of 1 mm. aluminum were used. In view of the great importance of these findings and our limited knowledge of the mode of action of the invisible radiations, it was decided to study the influence of irradiated food upon mice.