{ "types" : { "Bookmark" : { "pluralLabel" : "Bookmarks" }, "Publication" : { "pluralLabel" : "Publications" }, "GoldStandardPublication" : { "pluralLabel" : "GoldStandardPublications" }, "GoldStandardBookmark" : { "pluralLabel" : "GoldStandardBookmarks" }, "Tag" : { "pluralLabel" : "Tags" }, "User" : { "pluralLabel" : "Users" }, "Group" : { "pluralLabel" : "Groups" }, "Sphere" : { "pluralLabel" : "Spheres" } }, "properties" : { "count" : { "valueType" : "number" }, "date" : { "valueType" : "date" }, "changeDate" : { "valueType" : "date" }, "url" : { "valueType" : "url" }, "id" : { "valueType" : "url" }, "tags" : { "valueType" : "item" }, "user" : { "valueType" : "item" } }, "items" : [ { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2d4c6f9a31ee0320fc3be6307a85d6c4e/inspo5", "tags" : [ "Titin","Simtech","muscle","Contractile","Stretch","physiology","Muscle","behaviour","Sarcomere","Skeletal" ], "intraHash" : "d4c6f9a31ee0320fc3be6307a85d6c4e", "interHash" : "c1587910394340ebda12596b663f7b66", "label" : "Eccentric muscle contractions : from single muscle fibre to whole muscle mechanics", "user" : "inspo5", "description" : "", "date" : "2025-02-03 10:48:28", "changeDate" : "2025-02-03 11:10:28", "count" : 5, "pub-type": "article", "journal": "Pflügers Archiv","publisher":"Springer", "year": "2023", "url": "", "author": [ "André Tomalka" ], "authors": [ {"first" : "André", "last" : "Tomalka"} ], "volume": "475","pages": "421-435","abstract": "Eccentric muscle loading encompasses several unique features compared to other types of contractions. These features include increased force, work, and performance at decreased oxygen consumption, reduced metabolic cost, improved energy efficiency, as well as decreased muscle activity. This review summarises explanatory approaches to long-standing questions in terms of muscular contraction dynamics and molecular and cellular mechanisms underlying eccentric muscle loading. Moreover, this article intends to underscore the functional link between sarcomeric components, emphasising the fundamental role of titin in skeletal muscle. The giant filament titin reveals versatile functions ranging from sarcomere organisation and maintenance, providing passive tension and elasticity, and operates as a mechanosensory and signalling platform. Structurally, titin consists of a viscoelastic spring segment that allows activation-dependent coupling to actin. This titin-actin interaction can explain linear force increases in active lengthening experiments in biological systems. A three-filament model of skeletal muscle force production (mediated by titin) is supposed to overcome significant deviations between experimental observations and predictions by the classic sliding-filament and cross-bridge theories. Taken together, this review intends to contribute to a more detailed understanding of overall muscle behaviour and force generation\u2014from a microscopic sarcomere level to a macroscopic multi-joint muscle level\u2014impacting muscle modelling, the understanding of muscle function, and disease.", "issn" : "1432-2013", "language" : "eng", "doi" : "10.1007/s00424-023-02794-z", "bibtexKey": "tomalka2023eccentric" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/213d1c527b422f0c2fbfb26d98885b1f6/inspo5", "tags" : [ "Blebbistatin","damping","Cross-bridge","Mechanosensing","Signaling","Mechanical","Contractile","power","Muscle","behaviour","block","Sarcomere" ], "intraHash" : "13d1c527b422f0c2fbfb26d98885b1f6", "interHash" : "1a1ddb22b3fc4a98ff638b17f957aa71", "label" : "Force re-development after shortening reveals a role for titin in stretch-shortening performance enhancement in skinned muscle fibres", "user" : "inspo5", "description" : "", "date" : "2024-08-28 13:42:24", "changeDate" : "2025-02-11 20:09:58", "count" : 6, "pub-type": "article", "journal": "Journal of Experimental Biology","publisher":"The Company of Biologists", "year": "2024", "url": "http://dx.doi.org/10.1242/jeb.247377", "author": [ "André Tomalka","Sven Weidner","Daniel Hahn","Wolfgang Seiberl","Tobias Siebert" ], "authors": [ {"first" : "André", "last" : "Tomalka"}, {"first" : "Sven", "last" : "Weidner"}, {"first" : "Daniel", "last" : "Hahn"}, {"first" : "Wolfgang", "last" : "Seiberl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "abstract": "Stretch-shortening cycles (SSCs) involve muscle lengthening (eccentric contractions) instantly followed by shortening (concentric contractions). This combination enhances force, work, and power output compared to pure shortening (SHO), which is known as SSC-effect. Recent evidence indicates both cross-bridge-based (XB) and non-cross-bridge-based (non-XB, e.g., titin) structures contribute to this effect. This study analyzed force re-development following SSCs and SHO to gain further insight into the roles of XB and non-XB structures regarding the SSC-effect. Experiments were conducted on rat soleus muscle fibres (n=16) with different SSC velocities (30%, 60%, 85% of maximum shortening velocity) and constant stretch-shortening magnitudes (18% of optimum length). The XB inhibitor blebbistatin was used to distinguish between XB and non-XB contributions to force generation. Results showed SSCs led to significantly greater (1.02±.15 vs. 0.68±.09 [ΔF/Δt]; t(62)=8.61, p<.001, d=2.79) and faster (75 ms vs. 205 [ms]; t(62) = -6.37, p<.001, d=-1.48) force re-development compared to SHO in the control treatment. In the blebbistatin treatment, SSCs still resulted in greater (.11±.03 vs. .06±.01 [ΔF/Δt]; t(62) = 8.00, p<.001, d=2.24) and faster (3010±1631 vs. 7916±3230 [ms]; t(62) = -8.00, p<.001, d=-1.92) force re-development compared to SHO. These findings deepen our understanding of the SSC-effect, underscoring the involvement of non-XB structures like titin in modulating force production. This modulation likely involves complex mechanosensory coupling from stretch to signal transmission during muscle contraction.", "issn" : "1477-9145", "doi" : "10.1242/jeb.247377", "bibtexKey": "Tomalka_2024" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/23703361ba5364a5c2d4588e2de1b7f6e/inspo5", "tags" : [ "Give","Soleus","muscle","Contractile","Stretch","behavior","Skeletal" ], "intraHash" : "3703361ba5364a5c2d4588e2de1b7f6e", "interHash" : "91b7f9a1d1c44b2548f31012f256c179", "label" : "Impact of lengthening velocity on the generation of eccentric force by slow-twitch muscle fibers in long stretches", "user" : "inspo5", "description" : "", "date" : "2024-07-29 15:08:26", "changeDate" : "2025-02-03 10:59:12", "count" : 6, "pub-type": "article", "journal": "Pfluegers Archiv - European Journal of Physiology", "year": "2024", "url": "https://doi.org/10.1007/s00424-024-02991-4", "author": [ "Sven Weidner","André Tomalka","Christian Rode","Tobias Siebert" ], "authors": [ {"first" : "Sven", "last" : "Weidner"}, {"first" : "André", "last" : "Tomalka"}, {"first" : "Christian", "last" : "Rode"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "abstract": "After an initial increase, isovelocity elongation of a muscle fiber can lead to diminishing (referred to as Give in the literature) and subsequently increasing force. How the stretch velocity affects this behavior in slow-twitch fibers remains largely unexplored. Here, we stretched fully activated individual rat soleus muscle fibers from 0.85 to 1.3 optimal fiber length at stretch velocities of 0.01, 0.1, and 1 maximum shortening velocity, vmax, and compared the results with those of rat EDL fast-twitch fibers obtained in similar experimental conditions. In soleus muscle fibers, Give was 7\\%, 18\\%, and 44\\% of maximum isometric force for 0.01, 0.1, and 1 vmax, respectively. As in EDL fibers, the force increased nearly linearly in the second half of the stretch, although the number of crossbridges decreased, and its slope increased with stretch velocity. Our findings are consistent with the concept of a forceful detachment and subsequent crossbridge reattachment in the stretch's first phase and a strong viscoelastic titin contribution to fiber force in the second phase of the stretch. Interestingly, we found interaction effects of stretch velocity and fiber type on force parameters in both stretch phases, hinting at fiber type-specific differences in crossbridge and titin contributions to eccentric force. Whether fiber type-specific combined XB and non-XB models can explain these effects or if they hint at some not fully understood properties of muscle contraction remains to be shown. These results may stimulate new optimization perspectives in sports training and provide a better understanding of structure--function relations of muscle proteins.", "issn" : "1432-2013", "doi" : "10.1007/s00424-024-02991-4", "bibtexKey": "Weidner2024" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2f3d78410850201349b3420cb0f71115a/inspo5", "tags" : [ "Stomach","Uniaxial","Force","experiments","velocity","length","layer","relationship","muscle","Contractile","Separated","tensile","wall","Organ","properties" ], "intraHash" : "f3d78410850201349b3420cb0f71115a", "interHash" : "b79cfd3a81cd8360cba0a6d4729f7452", "label" : "Influence of layer separation on the determination of stomach smooth muscle properties.", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2022-07-19 09:10:56", "count" : 2, "pub-type": "article", "journal": "Pflugers Arch", "year": "2021", "url": "https://link.springer.com/article/10.1007/s00424-021-02568-5", "author": [ "Mischa Borsdorf","Markus Böl","Tobias Siebert" ], "authors": [ {"first" : "Mischa", "last" : "Borsdorf"}, {"first" : "Markus", "last" : "Böl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "473","pages": "911-920","abstract": "Uniaxial tensile experiments are a standard method to determine the contractile properties of smooth muscles. Smooth muscle strips from organs of the urogenital and gastrointestinal tract contain multiple muscle layers with different muscle fiber orientations, which are frequently not separated for the experiments. During strip activation, these muscle fibers contract in deviant orientations from the force-measuring axis, affecting the biomechanical characteristics of the tissue strips. This study aimed to investigate the influence of muscle layer separation on the determination of smooth muscle properties. Smooth muscle strips, consisting of longitudinal and circumferential muscle layers (whole-muscle strips [WMS]), and smooth muscle strips, consisting of only the circumferential muscle layer (separated layer strips [SLS]), have been prepared from the fundus of the porcine stomach. Strips were mounted with muscle fibers of the circumferential layer inline with the force-measuring axis of the uniaxial testing setup. The force\u2013length (FLR) and force\u2013velocity relationships (FVR) were determined through a series of isometric and isotonic contractions, respectively. Muscle layer separation revealed no changes in the FLR. However, the SLS exhibited a higher maximal shortening velocity and a lower curvature factor than WMS. During WMS activation, the transversally oriented muscle fibers of the longitudinal layer shortened, resulting in a narrowing of this layer. Expecting volume constancy of muscle tissue, this narrowing leads to a lengthening of the longitudinal layer, which counteracted the shortening of the circumferential layer during isotonic contractions. Consequently, the shortening velocities of the WMS were decreased significantly. This effect was stronger at high shortening velocities.", "language" : "English", "doi" : "doi:10.1007/s00424-021-02568-5", "bibtexKey": "borsdorf2021influence" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/2204dd2bdd095f61584b39198f567f745/inspo5", "tags" : [ "contractile","expenditure","cross-bridge","work","rFD","stretch","rFE","shortening","PN2A-1","muscle","inhibitor","history-effects","behavior" ], "intraHash" : "204dd2bdd095f61584b39198f567f745", "interHash" : "02ca247842c8357bc87ca9f9a0671742", "label" : "Cross-Bridges and Sarcomeric Non-cross-bridge Structures Contribute to Increased Work in Stretch-Shortening Cycles", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2024-07-05 14:54:15", "count" : 8, "pub-type": "article", "journal": "Frontiers in Physiology","publisher":"Frontiers Media SA", "year": "2020", "url": "https://doi.org/10.3389%2Ffphys.2020.00921", "author": [ "André Tomalka","Sven Weidner","Daniel Hahn","Wolfgang Seiberl","Tobias Siebert" ], "authors": [ {"first" : "André", "last" : "Tomalka"}, {"first" : "Sven", "last" : "Weidner"}, {"first" : "Daniel", "last" : "Hahn"}, {"first" : "Wolfgang", "last" : "Seiberl"}, {"first" : "Tobias", "last" : "Siebert"} ], "editor": [ "Tobias Siebert" ], "editors": [ {"first" : "Tobias", "last" : "Siebert"} ], "volume": "11", "doi" : "10.3389/fphys.2020.00921", "bibtexKey": "Tomalka_2020" } , { "type" : "Publication", "id" : "https://puma.ub.uni-stuttgart.de/bibtex/261fedf1d36ba0727ea70b4ebe0ccf080/inspo5", "tags" : [ "contractile","mechanical","damping","enhancement","performance","contractions","stretch","shortening","PN2A-1","muscle","power","eccentric","behavior" ], "intraHash" : "61fedf1d36ba0727ea70b4ebe0ccf080", "interHash" : "2c45e90e696b09a75331acf51aae74e4", "label" : "Power Amplification Increases With Contraction Velocity During Stretch-Shortening Cycles of Skinned Muscle Fibers", "user" : "inspo5", "description" : "", "date" : "2022-07-19 11:10:29", "changeDate" : "2024-07-05 14:53:03", "count" : 7, "pub-type": "article", "journal": "Frontiers in Physiology","publisher":"Frontiers Media SA", "year": "2021", "url": "https://doi.org/10.3389%2Ffphys.2021.644981", "author": [ "André Tomalka","Sven Weidner","Daniel Hahn","Wolfgang Seiberl","Tobias Siebert" ], "authors": [ {"first" : "André", "last" : "Tomalka"}, {"first" : "Sven", "last" : "Weidner"}, {"first" : "Daniel", "last" : "Hahn"}, {"first" : "Wolfgang", "last" : "Seiberl"}, {"first" : "Tobias", "last" : "Siebert"} ], "volume": "12","abstract": "Muscle force, work, and power output during concentric contractions (active muscle shortening) are increased immediately following an eccentric contraction (active muscle lengthening). This increase in performance is known as the stretch-shortening cycle (SSC)-effect. Recent findings demonstrate that the SSC-effect is present in the sarcomere itself. More recently, it has been suggested that cross-bridge (XB) kinetics and non-cross-bridge (non-XB) structures (e.g., titin and nebulin) contribute to the SSC-effect. As XBs and non-XB structures are characterized by a velocity dependence, we investigated the impact of stretch-shortening velocity on the SSC-effect. Accordingly, we performed in vitro isovelocity ramp experiments with varying ramp velocities (30, 60, and 85% of maximum contraction velocity for both stretch and shortening) and constant stretch-shortening magnitudes (17% of the optimum sarcomere length) using single skinned fibers of rat soleus muscles. The different contributions of XB and non-XB structures to force production were identified using the XB-inhibitor Blebbistatin. We show that (i) the SSC-effect is velocity-dependent\u2014since the power output increases with increasing SSC-velocity. (ii) The energy recovery (ratio of elastic energy storage and release in the SSC) is higher in the Blebbistatin condition compared with the control condition. The stored and released energy in the Blebbistatin condition can be explained by the viscoelastic properties of the non-XB structure titin. Consequently, our experimental findings suggest that the energy stored in titin during the eccentric phase contributes to the SSC-effect in a velocity-dependent manner.", "doi" : "https://doi.org/10.3389/fphys.2021.644981", "bibtexKey": "Tomalka_2021" } ] }