Figure 9. ATP release induced by a calcium ionophore is mediated by connexin hemichannels and Panx1 channels. Average levels of extracellular ATP after treatment with 2.5 μM 4Br-A23187 alone or preincubated with 5 μM CBX, a Panx1 channel blocker, 200 μM La³⁺, a connexin hemichannel blocker or combination of the 2 blockers, or with 18 β-GA (50 μM), a Panx1 channel and Cx HC blocker. Each bar represents the mean ± SEM of at least 4 experiments. The mean of each group was compared with ATP alone using a one way ANOVA and a post-test of Dunns. *P < 0.05, **P < 0.01.