title: Myofilament length dependent activation.
abstract: The Frank-Starling law of the heart describes the interrelationship between end-diastolic volume and cardiac ejection volume, a regulatory system that operates on a beat-to-beat basis. The main cellular mechanism that underlies this phenomenon is an increase in the responsiveness of cardiac myofilaments to activating Ca(2+) ions at a longer sarcomere length, commonly referred to as myofilament length-dependent activation. This review focuses on what molecular mechanisms may underlie myofilament length dependency. Specifically, the roles of inter-filament spacing, thick and thin filament based regulation, as well as sarcomeric regulatory proteins are discussed. Although the "Frank-Starling law of the heart" constitutes a fundamental cardiac property that has been appreciated for well over a century, it is still not known in muscle how the contractile apparatus transduces the information concerning sarcomere length to modulate ventricular pressure development.
authors.affiliation: Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Chicago, IL 60153, USA. pdetombe@lumc.edu
authors.forename: Pieter P
authors.initials: PP
authors.lastname: de Tombe
authors.forename: Ryan D
authors.initials: RD
authors.lastname: Mateja
authors.forename: Kittipong
authors.initials: K
authors.lastname: Tachampa
authors.forename: Younss
authors.initials: Y
authors.lastname: Ait Mou
authors.forename: Gerrie P
authors.initials: GP
authors.lastname: Farman
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Irving
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000818:Animals; D006321:Heart / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D009200:Myocardial Contraction / Q000502:physiology; D012518:Sarcomeres / Q000378:metabolism; D019210:Troponin I / Q000378:metabolism
chemical_list: D019210:Troponin I