OBJECTIVE To investigate the effect of oxygen glucose deprivation (OGD) on the glutamate release and the role of connexin 43 (Cx43) hemichannels in the OGD-induced glutamate release in primary cultured astrocytes. METHODS The astrocytes were randomly divided into four groups: normal control, OGD group, Gap26 (Cx43 hemichannel blocker) plus OGD group, Cx43-specific antisense oligodeoxynucleotide (ASODN) plus OGD group. In the OGD group, the astrocytes were cultured in the oxygen- and glucose-free culture medium (950 mL/L N₂ and 50 mL/L CO₂) for different durations (0, 15, 30, 60, 90, 120 minutes) at 37 Degrees Celsius, while the astrocytes in the control group were cultured in the ordinary culture medium. In the Gap26 plus OGD group or Cx43-ASODN plus OGD group, the astrocytes were incubated with Gap26 or Cx43-ASODN before and during the OGD. The extracelluar glutamate level was measured by high performance liquid chromatography (HPLC). RESULTS After OGD, the extracelluar glutamte level significantly increased, and reached the maximum (5.00±0.30) nmol/mL at 90 minutes of OGD, which was significantly higher than that of the normal control (2.36±0.15) nmol/mL(P<0.05). After treatment by Cx43-ASODN or Gap26, the increase was inhibited. At 90 minutes of OGD, the extracellular glutamate levels were respectively (4.02±0.18) nmol/mL and (3.93±0.32) nmol/mL. They were signficalty lower than that of the OGD group at the same time (P<0.05). CONCLUSIONS OGD induced glutamate release through Cx43 hemichannel in primary cultured astrocytes.