BEHAVIORAL AND CIRCULATORY RESPONSES TO X-IRRADIATION DELIVERED AT 200 RADS PER MINUTE TO WHOLE BODY AND TRUNK ONLY.

Macaca mulatta monkeys performing a continuous avoidance task received high energy x-irradiation delivered to either whole body or trunk only, at a dose rate of 200 rads per minute. Prior to and during the 88-minute period of irradiation, performance and blood pressure were monitored in both groups of subjects. Results support the concept that, at this dose rate of radiation exposure, immediate behavioral changes seen after absorption of relatively low superlethal doses reflect radiation effects on structures located within the trunk of the subject. No significant synergism between head and trunk effects appears to exist. At higher doses, prominent signs of direct central nervous system damage determine the behavioral effect. A phase of partially reversible hypotension is demonstrated after 1,200 to 1,500 rads are delivered at this dose rate. This hypotension appears to be due largely to an effect of radiation on trunk structures. Author