Pharmacological studies on chemical protectors against radiation, 13

X-Irradiation of mice in the range of 50-600 R results in rapid decrease in weight of the spleen and thymus until 3 days after the irradiation but the weight recovers thereafter. Testis weight decreases gradually from about 7 days after the irradiation and this decrease continues for about 30 days. This decrease in organ weight is in significant linear correlation with the irradiated dose. There was no specific effect of irradiation on the seminal vesicle, submaxillary gland, and kidneys. S-2-aminoethylisothiuronium-Br-HBr, 2-mercaptoethylamine-HCl, serotonin, epinephrine, and ethylisothiourea were ineffective against the specific decrease in the weight of the spleen, thymus, and testis by 400 R X-ray irradiation.