Comparative uptake of cimetidine by rat choroid plexus between the lateral and the 4th ventricles.

It is suggested that cimetidine interacts with the transport system for organic anions and oligopeptides in the rat lateral ventricular choroid plexus. In this study, we studied the transport system of cimetidine in the rat 4th ventricular choroid plexus to examine the heterogeneity in the ability to accumulate cimetidine between the lateral and the 4th ventricular choroid plexus. The similar time course of the accumulation of cimetidine was obtained between both choroid plexuses. Furthermore, the accumulation of cimetidine by the choroid plexus from the 4th ventricle was inhibited by unlabelled cimetidine (1 mM) and benzylpenicillin (1 mM) but not by tetraethylammonium (1 mM). These findings suggested that the rat choroid plexuses from the lateral and the 4th ventricle have similar characteristics in transporting cimetidine.