Objective      To construct the siRNA plasmid that can effectively inhibit expression of connexin 43 (Cx43) and detect the effect of inhibited Cx43 expression on release of glutamate from astrocytes (ASTs).       Methods      siRNA oligonucleotides targeting the Cx43 gene in rats were synthesized

and cloned into pGCsi.U6.neo.GFP vector. After plasmids were transfected into ASTs by electroblotting

effect of the silencing plasmids on expression of Cx43 was detected by Western blotting and immunofluorescence staining. Release of glutamate from ASTs was assayed with an ELISA kit. The number of  ASTs were calculated after DAPI staining.       Results      DNA sequencing showed that the target segments of Cx43 gene were correctly inserted into the plasmids and kept its correct reading frame. Forty-eight hours after the plasmids were transfected into AST

the expression level of Cx43 in ASTs and the glutamate released from ASTs were significantly lower than those in controls（P0.05）with no significant difference observed in the number of ASTs.       Conclusion      The siRNA vector we constructed can effectively inhibit the expression of Cx43 in ASTs of rats

and inhibition of Cx43 expression can reduce the release of glutamate from AST.