Objective:To study the expression of miRNA 320 a in the brain tissue of epileptic rats and analyze its effect on the expression of aquaporin 4(AQP4).Methods:All rats were performed with the intraperitoneal injection of lithium chloride(3 mmol/kg) and then the intraperitoneal injection of pilocarpine(30 mg/kg) 24 h later(injected twice) to prepare the epileptic model of Wistar rats.Rats in the control group were injected with the equal volume of normal saline.According to the Racine scale,rats with over stage 3 of epilepsy were chosen and the brain tissue was separated quickly and then stored at-80 ℃.The immunohistochemistry was used to detect the expression of aquaporin in the brain tissue of epileptic model and the Real-time PCR was employed to determine the difference in the expression of miRNA 320 a and AQP4 in the brain tissue of rats between the epileptic model group and control one.Five 5-day neonatal Wistar rats were chosen to collect the cerebral cortex and their primary astrocytes were separated and cultured.They were transfected with miRNA mimic and imitated to the endogenous miRNA 320 a to up-regulate the expression of miRNA 320 a.Results:In the model group,the expression of AQP4 was significantly higher than the control group(P<0.01).However,the expression of miRNA 320 a in the model group was lower than control group(P<0.05),which was negatively correlated to AQP4.In the primary astrocytes,the transfection of miRNA 320 a mimic could significantly reduce the expression of AQP4,while its inhibitor could up-regulate the expression of AQP4,which indicated that miRNA 320 a could reduce the expression of AQP4.Conclusions:In the primary astrocytes of rats,the miRNA 320 a could inhibit the expression of AQP4 and after adding the inhibitor of miRNA 320 a,the expression of AQP4 was up-regulated. Objective: To study the expression of miRNA 320 a in the brain tissue of epileptic rats and analyze its effect on the expression of aquaporin 4 (AQP4). Methods: All rats were performed with the intraperitoneal injection of lithium chloride (3 mmol / kg) and then the intraperitoneal injection of pilocarpine (30 mg / kg) 24 h later (injected twice) to prepare the epileptic model of Wistar rats. Rats in the control group were injected with the equal volume of normal saline. According to the Racine scale, rats with over stage 3 of epilepsy were chosen and the brain tissue was separated quickly and then stored at -80 ° C. The immunohistochemistry was used to detect the expression of aquaporin in the brain tissue of epileptic model and the Real-time PCR was employed to determine the difference in the expression of miRNA 320 a and AQP4 in the brain tissue of rats between the epileptic model group and control one. Five 5-day neonatal Wistar rats were chosen to collect the cerebral cortex and their primary astr ocytes were separated and cultured. The were were transfected with miRNA mimic and imitated to endogenous miRNA 320 a. upregulated expression of miRNA 320 a. Results: In the model group, the expression of AQP4 was significantly higher than the control group ( P <0.01) .Wowever, the expression of miRNA 320 a in the model group was lower than control group (P <0.05), which was negatively correlated to AQP4.In the primary astrocytes, the transfection of miRNA 320 a mimic could significantly the expression of AQP4, while its inhibitor could up-regulate the expression of AQP4, which indicates that miRNA 320 a could reduce the expression of AQP4.Conclusions: In the primary astrocytes of rats, the miRNA 320 a could inhibit the expression of AQP4 and after adding the inhibitor of miRNA 320 a, the expression of AQP4 was up-regulated.