Propyl gallate, a strong antioxidant, increases the Ca2+ sensitivity of cardiac myofilament.

Ca(2+) sensitizers are cardiotonic agents that directly increase the Ca(2+) sensitivity of cardiac myofilament. To find a novel Ca(2+) sensitizer, we have screened a group of phenolic compounds by examining their effects on the Ca(2+)-dependent force generation in cardiac muscle fibers. We found that propyl gallate, a strong antioxidant, increased the Ca(2+) sensitivity of cardiac myofilament in a dose-dependent and reversible manner. The present study indicates that propyl gallate is a novel type of Ca(2+) sensitizer with antioxidant activity, which might be more beneficial for the treatment of congestive heart failure associated with oxidative stress than existing Ca(2+) sensitizers.