In vivo Measurement of Radiophosphorus and Radiostrontium Absorption in Rats. ∗

Abstract

Summary

1. An in vivo method has been described for studying radiophosphorus and radiostrontium absorption from the intestinal tract in rats. The method is simple, avoids surgical trauma and permits visualization of the absorption process in individual animals. Rate of absorption at various times may also be estimated. This is not possible with the standard balance studies. Anesthesia is not necessary, though no difference of Sr⁸⁹ absorption was found when anesthesia was used. 2. Absorption of radiophosphorus was very rapid, reaching a peak at 30 minutes. In most animals, there was a delay of 20–30 minutes before significant amounts of radiostrontium were absorbed, and the whole process was slower. 3. It was possible to measure radiostrontium absorption on two different occasions in the same animal, first with Sr⁸⁹ and then with Sr⁸⁵. This should prove of value in studying factors affecting strontium absorption.