The Study of Expression of P-glycoprotein in Hippocampus in a Chronic Epileptic SD Rat Model

Objective To explore the relationship between the P-glycoprotein(P-gp) expression in hippocampus in the kindled model and the drug resistance in the intractable epilepsy.Methods The kindled model were prepared in Sprague-Dawley(SD) rats by constant intraperitoneal injection of pentylenetetrazol(PTZ) at subthreshold dosages.P-gp expression was detected in hippocampus from different groups of experimental rats by immunohistochemistry method.Results 63.3% rats were fully kindled.There was no P-gp positive signal in hippocampus in normal rats.Positive cells were detected in the nonkindled rats and in the kindled rats,especially in capillary endothelial cells and some astrocytes,but not in neurons.P-gp expression in hippocampus was more increased in the kindled rats than that in the nonkindled rats(P0.01).Conclusion Chronic seizures-induced overexpression of P-gp,especially in capillary endothelial cells could explain the drug resistance in intractable epilepsy.