[Effect of astrocytes with different degrees of proliferation on multidrug resistance gene expression in rats with epilepsy].

Objective: To study the relationship of activated astrocytes and multidrug resistance gene (MDR) expression in rats with epilepsy.
Methods: Astrocytes of neonatal Sprague-Dawley rats were separated and cultured. The cultured cells of passage 3 were activated by TNF-α for 2, 24 or 48 hrs. The culture media of cells with different degrees of proliferation were infused to the lateral cerebral ventricle of rats with epilepsy. The expression of MDR in the brain tissue was ascertained by PCR, immunocytochemistry and Western blot.
Results: After 2 hrs of TNF-α stimulation, astrocytes began to proliferate, and reached a peak at 24 hrs. The expression of MDR in the brain tissue increased after infusion of culture medium of proliferated astrocytes in the TNF stimulation group compared with that in the control group without TNF stimulation. The level of MDR expression in the TNF stimulation group was positively correlated with the degrees of cell proliferation.
Conclusions: Proliferation of astrocytes can increase the expression of MDR in rats with epilepsy and is probably involved in the development of refractory epilepsy.