The Frank–Starling mechanism in vertebrate cardiac myocytes

摘要: The Frank-Starling law of the heart applies to all classes vertebrates. It describes how stretch cardiac muscle, up an optimum length, increases contractility thereby linking ejection filling. cellular mechanisms underlying response include increase in myofilament sensitivity for Ca2+, decreased lattice spacing and increased thin filament cooperativity. Stretching mammalian, amphibian fish myocytes reveal that functional peak sarcomere length (SL)-tension relationship occurs at longer SL non-mammalian classes. These findings correlate with vivo function as vertebrates, such fish, vary stroke volume a relatively larger extent than mammals. Thus, it seems length-dependent properties individual are modified accommodate differences organ function, high extensibility certain hearts is matched by their myocytes. Reasons between still be elucidated, however, structure mammalian ventricular myocytes, widths higher levels passive stiffness those from other vertebrate may implicated.