ETHANOL-INDUCED ASPARTATE AND TAURINE RELEASE FROM PRIMARY ASTROCYTE CULTURES

Exposure of primary astrocyte cultures to isosmotic ethanol from 10-100 mM led to both swelling of the cells and release of [H-3]taurine and D-[H-3]aspartate. Exposure to hyperosmotic ethanol, in the same concentration range, caused neither swelling nor release. Release was inhibited by the anion transport blocker L-644,711, already shown to inhibit amino acid release evoked by hyposmotic or high-potassium medium, conditions that also cause astrocytic swelling. Ethanol-induced release generally showed a decline in response to successive exposures to ethanol, and release was not dependent on extracellular calcium. Thus, the characteristics of swelling-induced release of amino acids by isosmotic ethanol seem to correspond to those of swelling-induced release from astrocytes due to exposure to hypotonic or high-K+ media. We discuss whether such effects may contribute to CNS damage after head injury and stroke.