Reduction of myocardial cross-bridge turnover rate in presence of EMD 53998, a novel Ca2+-sensitizing agent

Autor: Leijendekker, Wim J., Herzig, Joachim W.
Zdroj: Pflügers Archiv European Journal of Physiology; July 1992, Vol. 421 Issue: 4 p388-390, 3p
Abstrakt: We have studied the effect of EMD 53998 (5-(1-(3, 4-dimethoxybenzoyl)-1,2,3,4-tetrahydrochinolin-6-yl)-6-methyl-3, 6-dihydro-2H-1,3,4-thiadiazin-2-one) on cross-bridge turnover rate at varying Ca2+ 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. The results indicate that the turnover rate of myocardial cross-bridges was reduced in the presence of EMD 53998 at low Ca2+ concentrations (pCa=6.25), but not at higher Ca2+ concentrations (pCa=5.85).
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