Figure 2.

PKCɛ is a major PKC isoform to regulate Ca²⁺ sparks in airway SMCs in the absence of functional IP₃Rs. (A) Effect of the PKC activator phorbol-12-myristate-13-acetate (PMA) on Ca²⁺ sparks in PKCɛ^+/+ cells after treatment with xestospogin-C. Original recordings of Ca²⁺ sparks in a PKCɛ^+/+ cell before and after application of PMA (50 nM) for 8 minutes after treatment with xestospongin-C (10 μM) for 8 minutes. Bar graphs summarize the effect of PMA on the frequency and amplitude of Ca²⁺ sparks in PKCɛ^+/+ cells. (B) Quantification of the effect of 50 nM PMA on the frequency and amplitude of Ca²⁺ sparks in PKCɛ^−/− cells after treatment with xestospogin-C (10 μM) for 8 minutes. Data are presented as means (±SEM). *P < 0.05 compared with control.