monensin and Reperfusion-Injury

Reperfusion of cultured rat astrocytes with Ca(2+)-containing medium after exposure to Ca(2+)-free medium for a short time caused an increase in intracellular Ca2+ ([Ca2+]i), and delayed cell death (Ca2+ paradox-like injury). Exposure of astrocytes to Ca(2+)-free medium caused a marked release of taurine. Taurine (3-30 mM) reduced the reperfusion-induced increase in [Ca2+]i and attenuated the delayed glial cell death. Glycine, GABA and beta-alanine did not affect reperfusion-induced cell toxicity. The protective effect of taurine required addition at an early time during reperfusion. Ouabain and monensin mimicked reperfusion injury and their toxicity was also reduced by taurine. Taurine (3-30 mM) inhibited dose-dependently 45Ca2+ uptake stimulated by ouabain and monensin in astrocytes. These findings suggest that taurine has a protective effect against reperfusion injury via an inhibition of Na+/Ca2+ exchange activity in the reverse mode.

Topics: Animals; Animals, Newborn; Astrocytes; beta-Alanine; Calcium; Cell Survival; Cells, Cultured; Cerebral Cortex; gamma-Aminobutyric Acid; Glycine; Kinetics; Monensin; Neuroprotective Agents; Ouabain; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Taurine; Time Factors