Muscle active force-length curve explained by an electrophysical model of interfilament spacing.

ABSTRACT: The active isometric force-length relation (FLR) of striated muscle sarcomeres is central to understanding and modeling muscle function. The mechanistic basis of the descending arm of the FLR is well explained by the decreasing thin:thick filament overlap that occurs at long sarcomere lengths. The mechanistic basis of the ascending arm of the FLR (the decrease in force that occurs at short sarcomere lengths), alternatively, has never been well explained. Because muscle is a constant-volume system, interfilament lattice distances must increase as sarcomere length shortens. This increase would decrease thin and thick-filament electrostatic interactions independently of thin:thick filament overlap. To examine this effect, we present here a fundamental, physics-based model of the sarcomere tha

SUBMITTER: Rockenfeller R 

PROVIDER: S-EPMC9199101 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature