Leijendekker W J, Herzig J W
Department Research CVS, Ciba-Geigy Limited, Basle, Switzerland.
Pflugers Arch. 1992 Jul;421(4):388-90. doi: 10.1007/BF00374228.
We have studied the effect of EMD 53998 (5-(1-(3,4-dimethoxybenzoyl)-1,2,3,4-tetrahydrochinolin-6-yl)-6-me thyl-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 greater than or equal to 6.25), but not at higher Ca2+ concentrations (pCa less than or equal to 5.85).
我们研究了EMD 53998（5-(1-(3,4-二甲氧基苯甲酰基)-1,2,3,4-四氢喹啉-6-基)-6-甲基-3,6-二氢-2H-1,3,4-噻二嗪-2-酮）在不同钙离子浓度下对横桥转换速率的影响。通过三磷酸腺苷酶测量和对持续激活纤维的力学特性测定来估计横桥循环速率，假定后者反映横桥动力学。结果表明，在低钙离子浓度（pCa大于或等于6.25）下，EMD 53998存在时心肌横桥的转换速率降低，但在较高钙离子浓度（pCa小于或等于5.85）下则不然。
