Constitutive Properties of Adult Mammalian Cardiac Muscle Cells

Abstract

Changes in viscous damping and myofilament activation in combination may cause pressure-hypertrophied cardiocytes to resist changes in shape during diastole and contribute to diastolic dysfunction.

Constitutive properties of hypertrophied myocardium: cellular contribution to changes in myocardial stiffness

“…The first three steps were accomplished in our previous studies (43,52,53). The last two steps were taken in the current study.…”

“…After the baseline stretches, colchicine was added to the buffer to achieve a final concentration of 10 Ϫ5 M. This concentration, which was higher then that used in isolated cardiocyte studies, was chosen to ensure thorough diffusion throughout the muscle (43,52,53). After treatment with colchicine for 90 min, Lmax was determined, and another series of four uniaxial variable rate stretches were performed.…”

“…To test the first part of this hypothesis, we examined the effects of POH on the constitutive properties of cardiocytes isolated from hypertrophied myocardium and found that 1) POH caused significant alterations in the cardiocyte viscoelastic properties, 2) the POH-induced increase in cardiocyte viscous damping was associated with alterations in the intracellular cytoskeleton, and 3) these abnormalities in the cellular cytoskeleton could be acutely corrected and that correcting these cellular abnormalities completely normalized viscous damping in the POH cardiocytes (43,53).…”

Cytoskeletal networks and the regulation of cardiac contractility: microtubules, hypertrophy, and cardiac dysfunction

“…What then is the precise physical nature of the impediment to contraction produced by microtubule network densification? I addressed this question in a collaboration with N. Wang and M. R. Zile by directly probing the viscoelastic properties of the tensegrity network of physically interrelated cytoskeletal filaments in living cardiocytes (26) and then confirming these findings at the level of whole cell and tissue mechanics (14,31). Figure 15 (top) shows the appearance of beads that are attached via integrin receptors to the cardiocyte cytoskeleton.…”

Biohybrid Walking Microrobot with Self-Assembled Cardiomyocytes

“…In this case, each heart muscle cell has longer pulsation and loses its force. Therefore, the information on the contractile force of the heart cell is expected to play an important role in finding the basic remedy and substitution for cells with heart disease [24]. Although force measurements at the cellular tissue and whole organ levels have been performed [25][26], influence from outside factors cannot be entirely excluded, giving rise to inaccurate measurements of the force of heart cells.…”