ShUT A. Statistic and kinetics models of muscle fiber contraction.

Dissertation presents physical and mathematical models of the processes of muscle fiber contraction. Applying the methods of statistical physics to alfa-spiral, as to the quasi-single crystal, and to vibrational excitations of exciton-soliton type, as to the quasi-particles in approach effective mass, which characterized by a certain impulse and effective mass, we calculating the force, which produce the separate excited myosin molecules. We have analytically obtained "force-length" dependence for single contraction of skeletal muscle. The dynamics of isometric contraction of muscle fiber is described. Changes of entropy and free energy are expected when muscle is lengthening. Temperature dependence of force and length of the contracted muscle is experimentally investigated. Within the framework of proposed model modified Hill equation is deduced, and physical content of its coefficients is found out. Two independent models of the possible connection between a change in the ion Са2+ concentration and the force response on this change. A number of estimations are obtained for the parameters of models, which characterize association - dissociation kinetics of actomiosin complex. A kinetic model, which describes influence of рН level of environment on ATP activity of myosin of skeletal muscles is built. The appearing of two maximums on the dependence curve of rate of ATP hydrolysis by a myosin on рН level, which is caused by four protons fermentation reaction participating is explained.