Figure 6. Blockade of Cd²⁺-induced ATP and GSH release by GJs inhibitor and Cx mimetic peptides.

(A–B) Cx43-LLC-PK1 cells were pretreated with 4 mM heptanol for 30 min or with Cx43 mimetic peptides Gap20 and Gap26 at the concentration of 100 μM for 1 h, and then exposed to 35 μM Cd²⁺ in the presence of the pretreated agents for additional 6 h ATP and GSH concentration in culture medium was measured. The data were expressed as the fold induction against basal level (mean ± S.E., n = 4). # p<0.01 and * p<0.05 versus Cd²⁺ alone, and ** <0.01 versus untreated control. (C) Time course effects of Cd²⁺ on LDH release. Cx43-LLC-PK1 cells were treated with 35 μM CdCl₂ for the indicated duration. The supernatants were collected and assayed for LDH activity. The data were expressed as fold of zero point control (mean ± S.E., n = 4).