Figure 3. S100A1 Restores Ca²⁺ Handling in Failing Human Myocardium.

(A) Representative Ca²⁺ transients and corresponding normalized transient decays under basal conditions from Ad-control-treated (red line) and Ad-S100A1–treated (green line) HFCMs paced at 1 Hz depict enhanced Ca²⁺ transient amplitudes and accelerated cytosolic Ca²⁺ removal by S100A1. (B) Representative tracings of caffeine-induced (10 mmol/l pulse) rise in cytosolic Ca²⁺ illustrates a greater amplitude in Ad-S100A1–treated cells (red line) compared with control cells (green line) reflecting enhanced SR Ca²⁺ load by S100A1. SR = sarcoplasmic reticulum; other abbreviations as in Figure 1.