Localization of cysteine sulfinic acid uptake sites in rat brain by quantitative autoradiography

In vitro autoradiography was employed to localize and quantify Na-dependent binding sites of [35S]cysteic acid (CA), an analog of cysteine sulfinic acid (CSA). The heterogeneous anatomical distribution and pharmacological specificity of [35S]CA differs from that of the glutamate/aspartate marker D-[3H]aspartate, and appears to represent a specific uptake site for CSA. These results suggest that CSA may act as an excitatory transmitter in the central nervous system.