Force-Dependent Recruitment from the Myosin Off State Contributes to Length-Dependent Activation.

ABSTRACT: Cardiac muscle develops more force when it is activated at longer lengths. The concentration of Ca²⁺ required to develop half-maximal force also decreases. These effects are known as length-dependent activation and are thought to play critical roles in the Frank-Starling relationship and cardiovascular homeostasis. The molecular mechanisms underpinning length-dependent activation remain unclear, but recent experiments suggest that they may include recruitment of myosin heads from the off (sometimes called super-relaxed) state. This manuscript presents a mathematical model of muscle contraction that was developed to investigate this hypothesis. Myosin heads in the model transitioned between an off state (that could not interact with actin), an on state (that could bind to actin),

SUBMITTER: Campbell KS 

PROVIDER: S-EPMC6084639 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature