Coordination of Ca2+ regulating and Ca2+ regulated processes in the study of muscle function.

Abstract

The self-organization of biological systems is, in part, described by dynamical order and cooperativity of system elements. Consideration of this, therefore, should form the infrastructure of future Exercise/Sport Biochemistry Research in Canada since a solely elemental focus, in its' interpretation, may not be meaningful if the synergy among system elements is not appreciated. This approach is illustrated through a description of the central role of Ca2+ metabolism in coordinating subcellular events associated with muscle contraction. The decline in force generating capabilities associated with extreme muscle use (e.g. endurance type exercise) is, in our view, due to an uncoupling of excitation-contraction coupling leading a Ca2+ imbalance. The observed dissolution of the myofibril ultrastructure and altered SR function reflect a loss of normal order and synergy amongst Ca2+ regulated and Ca2+ regulating processes which will lead to an upcoupling of oxidative phosphorylation. These apparently catastrophic events may, paradoxically, establish a new order in which energy utilizing systems attempt to keep pace with the abbreviated energy production system.