Aluminum chloride stimulates the release of endogenous glutamate, taurine and adenosine from cultured rat cortical astrocytes

Primary astrocyte cultures derived from neonatal rat cerebral cortex were treated for 5 min with 0.5 mM or 5.0 mM AlCl₃, and the incubation medium was analyzed by HPLC for the content of released glutamate (Glu), taurine (Tau), serine (Ser) and the nucleoside adenosine (Ade). At 0.5 mM, AlCl₃ stimulated Tau release to about 170% of basal levels, but did not affect the release of the other compounds. Treatment with 5.0 mM AlCl₃ enhanced the release of Tau, Glu and Ade, to 800%, 1000% and 250%, respectively, but decreased the release of Ser to 70% compared to basal levels. The enhanced release of these neuroactive compounds from astrocytes may contribute to changes in neural transmission known to accompany exposure to aluminum.