Abstract
A radiographic method for studying the delay in gastric emptying in the rat caused by whole body irradiation has been applied to the investigation of two compounds which modify the effects of irradiation. The method may be of general use in the study of the action of drugs. Synkavit, which can potentiate the lethal effects of irradiation on tumours, caused a delay in gastric emptying. When Synkavit and irradiation were combined, a simple summation of the delays produced by each of these agents occurred. Cysteamine, which gives some protection against the lethal action of x-rays, also caused a delay in gastric emptying, it did not protect against the action of x-rays on stomach emptying.