Objective:To explore the possible involvement of Müller cell gliosis,ATP/ P2X7 receptors and RGC-5 apoptosis in vitro. Methods:We cultured and purificated rat retinal Müller cells,RGC-5. The concentration of extracellular ATP was quantified by bioluminescence assay. After adding the medium of DHPG-activated Müller cells Medium(conditioned medium /CM)to RGC-5 cells,TUNEL assay and Western blot of anti-and pro-apoptotic proteins were used to observe RGCs apoptosis. Immunofluorescence and Western blot were also used to detect the P2X7 expression of RGC-5 with CM. Results:DHPG induced an increasing ATP release from Müller cells. After adding the CM to RGC-5 cells,TUNEL assay showed a significantly increase RGCs apoptosis while P2X7 receptor blocker BBG reduced apoptosis of RGCs. Moreover,CM treatment of RGC-5 cells significantly increased Bax protein level and decreased Bcl-2 protein level,which was also mimicked by BzATP and blocked by BBG,respectively. Conclusion:The current study suggests that DHPG-activated Müller cells could aggravate RGCs apoptosis,while the release of ATP from Müller cells and the activation of P2X7 receptor in the RGC-5 might be involved in this process.