Force enhancement modeled by three filament model
ČIBERA, V., HERZOG, Force enhancement modeled by three filament model. Salzburg, Rakousko, 2015.
|Anglický název:||Force enhancement modeled by three filament model|
|Autoři:||Ing. Václav Čibera , Walter Herzog|
|Abstrakt EN:||The purpose of this study was to model the unexplained increase in force during and after active muscle stretching. Specifically, the aim was to theoretically simulate force during and after active muscle stretching at the single sarcomere and half sarcomere level. The simulations are based on a three filament sarcomere model consisting of the contractile protein actin and myosin, and the structural protein titin. The mathematical description of the three filament model is comprised of two main parts. The first part is based on the classical, two-state Huxley (1957) cross-bridge model, which captures the active, actin-myosin based cross-bridge forces. The second component of the model describes the passive forces produced in a sarcomere, which can be associated virtually exclusively with titin. When a sarcomere is stretched, titin acts as a molecular spring. The elastic properties of titin?s spring segments (the proximal and distal Immunoglobulin, Ig domains, the N2A and the PEVK regions) have been well described and they have been used here for simulating titin?s force-extension properties. Our simulations can explain the extra force observed in eccentric contractions, the reduced energy cost of eccentric contractions and the long lasting increase in force (force enhancement) following active sarcomere stretching.|