Reduction of myocardial cross-bridge turnover rate in presence of EMD 53998, a novel Ca super(2+)-sensitizing agent

We have studied the effect of EMD 53998 on cross-bridge turnover rate at varying Ca super(2+) concentrations. Cross-bridge cycling rate was estimated both by adenosine triphosphatase measurements and determination of mechanical characteristics of constantly activated fibres, which is assumed to reflect cross-bridge kinetics.