Studies on structural changes of F-actin and myosin in living, intact and damaged muscle fibres by means of polarized ultraviolet fluorescence microscopy.

By means of polarized ultraviolet fluorescence microscopy the structural changes of F-actin and myosin were discovered at the changing a functional state of a living muscle fibre and during spreading degeneration (Zenker's necrosis). The character of conformational changes of F-actin and myosin at activation, contraction, contracture and rigor is similar, but the number of changed macromolecules depends on a fibre state. At fibre local damage in its morphological intact parts there was found an alternation of zones, reflecting two states unusual for a fibre. During spreading degeneration these states transform into irreversible contracture and then into rigor. Similar changes were observed in muscle fibres obtained from denervated muscles.