Figure 4

Assessing the recovery of [Ca²⁺] _i following Ca²⁺-uncaging in ASM cells derived from asthmatic and non-asthmatic donors. (A) Representative examples of changes in [Ca²⁺]_i on photolysis of the NP-EGTA Ca²⁺ cage and the subsequent rate of recovery to pre-uncaging levels of [Ca²⁺]_i. Changes in [Ca²⁺]_i are shown for ASM cells in the absence (blue line) or presence (green line) of the SERCA inhibitor, CPA (10 μM). Inset example photographs of Ca²⁺ uncaging using a confocal microscope before (i), during (ii) and after (iii) the 405 nm laser flash. (B) Mean Ca²⁺ uncaging recovery rates (K_-CPA) without SERCA inhibition in ASM cells from normal (n = 10) and asthma (n = 10) donors. (C) Mean Ca²⁺ uncaging recovery rates when SERCA is inhibited (K_+CPA) in ASM cells from normal (n = 10) and asthma (n = 12) donors. (D) The difference between K_-CPA and K_+CPA (∆K), which represents primarily trans-plasmalemmal efflux of Ca²⁺ in ASM cells, is also plotted for each normal (n = 10) and asthmatic (n = 12) donor. Symbol key: filled circles: GINA 1–3; open circles: GINA 4–5 filled squares: non-asthmatic donors. Data are shown as mean (SEM) and analyzed by Student’s t-test.