Figure 5.

Modification of RyR2 activity by FKBP12.6 homozygous gene deletion or RyR2 heterozygous gene deletion fails to prevent the effect of PKCɛ inhibition and activation on Ca²⁺ sparks in airway SMCs in the absence of functional IP₃Rs. (A) Effect of PKCɛ peptide inhibitor on Ca²⁺ sparks in FKBP12.6^−/− cells in the presence of xestospogin-C. Line-scanning recordings of Ca²⁺ sparks were recorded in an FKBP12.6^−/− cell before and after application of 100 μM PKCɛ peptide inhibitor (PKCɛ pept) for 8 minutes after treatment with 10 μM xestospogin-C for 8 minutes. Bar graphs summarize the effect of PKCɛ peptide inhibitor on the frequency and amplitude of Ca²⁺ sparks in FKBP12.6^−/− cells. (B) Effect of 50 nM PMA on Ca²⁺ sparks in FKBP12.6^−/− cells after treatment with 10 μM xestospogin-C for 8 minutes. (C) Effect of 100 μM PKCɛ peptide inhibitor on Ca²⁺ sparks in RyR2^+/− cells after treatment with 10 μM xestospogin-C for 8 minutes. Data are presented as means (±SEM). *P < 0.05 compared with control.