The effect of X rays, DTPA, and aspirin on the absorption of plutonium from the gastrointestinal tract of rats.

To measure the effect of radiation on plutonium transport, rats that were exposed to 250-kVp X rays were given 238Pu 3 days afterwards by either gavage or injection into a ligated segment of the duodenum. In a second group of experiments, rats were either injected intraduodenally with 238Pu-DTPA or administered the chelate intravenously and the 238Pu by gavage. In a third experiment, rats that had been gavaged with 200 or 400 mg/kg/day of aspirin for 2 days were injected intragastrically with 238Pu nitrate. Results of the first experiment showed a dose-dependent increase in 238Pu absorption between 800 and 1500 rad of lower-body X irradiation. Intravenous or intraduodenal injections of DTPA caused a marked increase in 238Pu absorption but resulted in decreased plutonium deposition in the skeleton and liver. Retention of 238Pu in the skeleton of rats given aspirin was double that of controls, but the effect on plutonium absorption was less marked than that of DTPA.