%0 Journal Article %1 Carlo_Danesini_2024 %A Carlo Danesini, Paolo %A Heim, Maximilian %A Tomalka, André %A Siebert, Tobias %A Ates, Filiz %D 2024 %E Siebert, Tobias %I Elsevier BV %J Journal of Biomechanics %K EXC2075 PN2 PN2-8Siebert selected %P 112134 %R 10.1016/j.jbiomech.2024.112134 %T Endomysium determines active and passive force production in muscle fibers %U http://dx.doi.org/10.1016/j.jbiomech.2024.112134 %V 168 %X Connective tissues can be recognized as an important structural support element in muscles. Recent studies have also highlighted its importance in active force generation and transmission between muscles, particularly through the epimysium. In the present study, we aimed to investigate the impact of the endomysium, the connective tissue surrounding muscle fibers, on both passive and active force production. Pairs of skeletal muscle fibers were extracted from the extensor digitorum longus muscles of rats and, after chemical skinning, their passive and active force–length relationships were measured under two conditions: (i) with the endomysium between muscle fibers intact, and (ii) after its dissection. We found that the dissection of the endomysium caused force to significantly decrease in both active (by 22.2 % when normalized to the maximum isometric force; p < 0.001) and passive conditions (by 25.9 % when normalized to the maximum isometric force; p = 0.034). These findings indicate that the absence of endomysium compromises muscle fiber’s not only passive but also active force production. This effect may be attributed to increased heterogeneity in sarcomere lengths, enhanced lattice spacing between myofilaments, or a diminished role of trans-sarcolemmal proteins due to dissecting the endomysium. Future investigations into the underlying mechanisms and their implications for various extracellular matrix-related diseases are warranted.

@article{Carlo_Danesini_2024, abstract = {Connective tissues can be recognized as an important structural support element in muscles. Recent studies have also highlighted its importance in active force generation and transmission between muscles, particularly through the epimysium. In the present study, we aimed to investigate the impact of the endomysium, the connective tissue surrounding muscle fibers, on both passive and active force production. Pairs of skeletal muscle fibers were extracted from the extensor digitorum longus muscles of rats and, after chemical skinning, their passive and active force–length relationships were measured under two conditions: (i) with the endomysium between muscle fibers intact, and (ii) after its dissection. We found that the dissection of the endomysium caused force to significantly decrease in both active (by 22.2 % when normalized to the maximum isometric force; p < 0.001) and passive conditions (by 25.9 % when normalized to the maximum isometric force; p = 0.034). These findings indicate that the absence of endomysium compromises muscle fiber’s not only passive but also active force production. This effect may be attributed to increased heterogeneity in sarcomere lengths, enhanced lattice spacing between myofilaments, or a diminished role of trans-sarcolemmal proteins due to dissecting the endomysium. Future investigations into the underlying mechanisms and their implications for various extracellular matrix-related diseases are warranted.}, added-at = {2025-02-14T11:14:18.000+0100}, author = {Carlo Danesini, Paolo and Heim, Maximilian and Tomalka, André and Siebert, Tobias and Ates, Filiz}, biburl = {https://puma.ub.uni-stuttgart.de/bibtex/283fba02b010557af3f547c378cdb6de6/simtechpuma}, doi = {10.1016/j.jbiomech.2024.112134}, editor = {Siebert, Tobias}, interhash = {2d12b002242e8974ec406082ad65e8b3}, intrahash = {83fba02b010557af3f547c378cdb6de6}, issn = {0021-9290}, journal = {Journal of Biomechanics}, keywords = {EXC2075 PN2 PN2-8Siebert selected}, language = {English}, month = {05}, pages = 112134, publisher = {Elsevier BV}, timestamp = {2025-02-14T11:14:18.000+0100}, title = {Endomysium determines active and passive force production in muscle fibers}, url = {http://dx.doi.org/10.1016/j.jbiomech.2024.112134}, volume = 168, year = 2024 }