The process by which cardiac excitation triggers a rise in intracellular Ca2+ and contraction is known as excitation-contraction coupling (reviewed by [ 80, 81]).
Therefore, caged compounds of low molecular weight, which are commercially available, have been used effectively to study the mechanisms of temporal biological phenomena, such as muscle contraction, intracellular signaling, and neurotransmission.
Our study further revealed an age-associated disparity in physiological leptin level-elicited responsiveness in cardiomyocyte contraction, intracellular Ca2+ handling and O2− production.
Skeletal muscle fibers can control capillary growth by releasing VEGF from intracellular vesicles during contraction [ 26].
The level of intracellular Ca+ available for contraction determines which of the two pathways will be activated.
This subsequently increases the force of contraction, since intracellular calcium ions are responsible for initiating the shortening of muscle cells.
The rise in the level of intracellular calcium, however, initiates contraction through a mechanism that differs substantially from that in striated muscle.
Indeed, gap junction blockers either increase or decrease the contraction and intracellular calcium to phenylephrine in rat mesenteric arteries [24], [29].
In small vessels, gap junctions are usually mainly involved in spontaneous oscillations of membrane potential, intracellular calcium concentration and contraction [24], [28], [29].
The rise in intracellular free Ca2+ initiates contraction through the binding of Ca2+ to myofilaments, whereas myocyte relaxation is promoted by decrease in intracellular Ca2+ and dissociation of Ca2+ from the myofilaments.
