A low-cost 2D sarcomere model to demonstrate titin related mechanisms for force production

Adv Physiol Educ. 2023 Dec 7. doi: 10.1152/advan.00090.2023. Online ahead of print.ABSTRACTGiven the recently proposed three-filament theory of muscle contraction, we present a low-cost physical sarcomere model aimed at illustrating the role of titin in the production of active force in skeletal muscle. Using inexpensive materials, it is possible to illustrate actin-myosin cross-bridge interactions between the thick and thin filaments and demonstrate the two different mechanisms by which titin is thought to contribute to active and passive muscle force. Specifically, the model illustrates how titin, a molecule with spring-like properties, may increase its stiffness by binding free calcium upon muscle activation and reducing its extensible length by attaching itself to actin, resulting in the greater force generating capacity after an active than a passive elongation that has been observed experimentally. The model is simple to build and manipulate, and demonstration to high school students was shown to result in positive perception and improved understanding of the otherwise complex titin related mechanisms of force production in skeletal and cardiac muscles.PMID:38059284 | DOI:10.1152/advan.00090.2023
Source: Adv Physiol Educ - Category: Universities & Medical Training Authors: Source Type: research