Absorption of Organic Arsenical Compounds from the Rat Small Intestine

Abstract

1. The pentavalent organic arsenical compounds carbarsone, tryparsamide, and cacodylic acid were absorbed from the rat small intestine at rates directly proportional to concentration over a 100-fold range.

2. Absorption half-times (min) were: carbarsone, 87; tryparsamide, 184; and cacodylic acid, 201.

3. Absorption rates (first-order rate constants) ranked in the same order as the CHCl₃-to-water partition coefficients of the compounds as measured at pH 5·3.

4. The results suggested that these organo-metallic compounds are absorbed mainly by a process of simple diffusion.