In developing the technology, scientists analyzed how sarcomeres
generate tension coupled with alterations in calcium cycling, which is critical to heart function.
Scanning electron microscopy analysis showed structure damage of sarcomere
Z-disks and presence of pleomorphic dense structures near Z-disks or between myofibrils.
2+] concentrations activates calpains 1 and 2 (Cap-1 and Cap-2), which in turn promote sarcomere
disintegration and myofibrillar proteins liberation.
37) The arrowheads point away from the Z-band of sarcomere
Myofiber disarray is displayed by disordered myocyte bundles, individual myocytes, and contractile elements within sarcomeres
Objectives: (1) To see whether movement of Z discs on either side of A band toward the center of a sarcomere
is possible when contraction is occurring in two adjacent sarcomeres
It is mainly caused by mutations in genes encoding sarcomere
A number of peripheral factors prevent the activity of masticatory muscles from being pushed towards both sides by the motor unit, such as the presence of a preferred masticatory side, occlusal stability, food size and consistency, and mandible orientation, which is in turn related to the length of the sarcomere
Critical to this process is ATP hydrolysis that provides energy for the enzymatic activity of the myosin head which generates a single articulation of the myosin head and molecular movement of actin past myosin which shortens the sarcomere
We previously established that, using skinned muscle fibers placed in a Ca buffer, each sarcomere
exhibited stable auto-oscillation of contraction and elongation under the fixed Ca concentration of approximately 1 uM, through careful measurements of muscle fiber tension (especially using thin bundles of myofibrils ~1 um in diameter); we termed this phenomenon as spontaneous oscillatory contraction (SPOC) (see recent review by S.
The literature describes several viscoelastic properties of skeletal muscle (stress relaxation, creep, and hysteresis) that may explain increased sarcomere
compliance and the lengthening process, but there is still some debate as to how much of the change is mechanical/structural and how much is functional/neurological (3), (4).
Seidman CE, Seidman JG (2011) Identifying sarcomere
gene mutations in hypertrophic cardiomyopathy: a personal history.