Fig. 5.

siRNA-mediated knockdown of PI3Kγ attenuated IL-13-augmented Ca²⁺ oscillations in primary mouse ASM cells. A, a concentration of 1 μM ACh induced Ca²⁺ mobilization (Fura-2 as a probe) of mouse ASM cells. The intracellular Ca²⁺ concentration is presented as the ratio of the fluorescence intensities at an excitation of 340 nm compared with 380 nm (F340/F380). These data were quantified and are shown in B and C. B and C, in control and IL-13-treated ASM cells, siRNA-mediated knockdown of PI3Kγ only partially reduced the initial Ca²⁺ transient (B) but more markedly attenuated Ca²⁺ oscillations (C) of ASM cells in response to ACh. Data are means ± S.E. and represent at least 30 cells from three separate experiments performed on multiple days. Statistical comparisons used ANOVA with the Bonferroni correction. Neg, negative.