Figure 2.

Hemichannels opening induced by OS requires elevated [Ca²⁺]_i. (A) Hemichannel opening induced by H₂O₂ is blocked by depletion of [Ca²⁺]_i. MLO-Y4 cells were pre-incubated with 5 μmol·L⁻¹ BAPTA-AM or 5 μmol·L⁻¹ U73122 for 20 min and then were incubated with 0.3 mmol·L⁻¹ H₂O₂ for 30 min. EtBr dye uptake was performed and imaged by snapshot. The degree of dye uptake was quantified by Image J. The dashed line indicates the normalized basal dye uptake value. H₂O₂ treatment versus all other conditions, **P<0.01, n=3. (B) BAPTA-AM does not block the activation of Cx43 hemichannels induced by media dropping. MLO-Y4 cells were pre-treated with 5 μmol·L⁻¹ BAPTA-AM and were stimulated by media dropping to induce Cx43 hemichannels opening. EtBr dye uptake was performed and imaged by snapshot. The degree of dye uptake was quantified by Image J. The dashed line indicates the normalized basal dye uptake value. Non-dropping control with BAPTA-AM versus dropping with or without BAPTA-AM, ***P<0.001, n=3.