Taylor T W, Goto Y, Suga H
National Cardiovascular Center Research Institute, Osaka, Japan.
Heart Vessels. 1992;7(4):200-5. doi: 10.1007/BF01744605.
A mathematical model incorporating Huxley's sliding filament crossbridge muscle model coupled with parallel and series elastic components was simulated to examine force-length relations under different external calcium concentrations. Several researchers have determined experimentally in both papillary muscle preparations and in situ heart experiments that the calcium concentration (or effective concentration from inotropic agents) will affect the strength and convexity of the cardiac muscle fiber force-length relations. Simulations were performed over a several-order-of-magnitude range of calcium concentrations in isometric contractions and these showed that the force-length curve convexity was changed. Simulation results demonstrated that increasing the stiffness in the model contractile element or series elasticity element did not change the force-length convexity. Increasing the series elasticity element stiffness did slightly change the shape of the force-length curve. The model predicts that the curve convexity changes as a result of the calcium-troponin interactions.
模拟了一个结合赫胥黎滑动细丝横桥肌肉模型以及平行和串联弹性成分的数学模型，以研究不同外部钙浓度下的力-长度关系。几位研究人员在乳头肌制备和原位心脏实验中均通过实验确定，钙浓度（或来自变力性药物的有效浓度）会影响心肌纤维力-长度关系的强度和凸度。在等长收缩中，针对几个数量级范围的钙浓度进行了模拟，结果表明力-长度曲线的凸度发生了变化。模拟结果表明，增加模型收缩元件或串联弹性元件的刚度并不会改变力-长度的凸度。增加串联弹性元件的刚度确实会略微改变力-长度曲线的形状。该模型预测，曲线凸度的变化是钙与肌钙蛋白相互作用的结果。
