Mechanisms of intracellular trigger signal transmission in muscles: Strategy of rearrangements in evolution of the contractile function

Abstract

The paper describes our concept about the existence of a certain strategy of rearrangements of ionic mechanisms of he intracellular trigger signal transmission in muscles during their contractile function evolution. It is shown that the rearrangements of muscles to accelerate the single (discrete) contraction cycle is accompanied by a change of mechanisms of external stimulus transduction into an intracellular trigger signal: direct activation of intracellular effectors by extracellular Ca2+ is replaced by indirect mechanisms of Ca2+-, then Ca2+- and Na+-induced, and in skeletal muscle fibers of vertebrates (SMFV) of Na+-induced Ca2+ release from the intracellular depot, sarcoplasmic reticulum. These rearrangements promoted an intensification of the Ca2+ intracellular mobilization to provide for the most complete pulse control of SMFV phasic contractions by the CNS and their protection from undesirable peripheral influences.