Effect of Phenytoin on Cortical Na+-K+-ATPase Activity in Global Ischemic Rat Brain

Abstract
Na+-K+-ATPase activity, water content, and Na+/K+ concentrations in the parietal cortex were measured in untreated and phenytoin-treated rats following global cerebral ischemia. Inhibitory effects of phenytoin treatment on brain edema and changes in Na+-K+ concentration with ischemia or ischemia followed by recirculation of varying intervals were assessed. The cortical Na+-K+-ATPase activity increased in the phenytoin-treated group during and after ischemia. Based on these results, we conclude that phenytoin provides ischemic brain protection by activating cortical Na+-K+-ATPase activity and by reducing intracellular Na+ and water content.