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Updated: May 19, 2026

In Vitro Assessment of Cardiac Function Using Skinned Cardiomyocytes
Published on: June 22, 2020
Titin-based tension in the cardiac sarcomere: molecular origin and physiological adaptations
Brian R Anderson1, Henk L Granzier
1Department of Physics, University of Arizona, Tucson, AZ 85724, USA.
Abstract:
The passive stiffness of cardiac muscle plays a critical role in ventricular filling during diastole and is determined by the extracellular matrix and the sarcomeric protein titin. Titin spans from the Z-disk to the M-band of the sarcomere and also contains a large extensible region that acts as a molecular spring and develops passive force during sarcomere stretch. This extensible segment is titin's I-band region, and its force-generating mechanical properties determine titin-based passive tension. The properties of titin's I-band region can be modulated by isoform splicing and post-translational modification and are intimately linked to diastolic function. This review discusses the physical origin of titin-based passive tension, the mechanisms that alter titin stiffness, and titin's role in stress-sensing signaling pathways.
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