[State of the contractile apparatus during the development of a pathological process in the muscles. V. The effect of Zenker's necrosis and of denervation atrophy on F-actin structure].

By means of polarized UV fluorescent microscopy, the state of F-actin was studied in single glycerinized muscle fibers from intact, locally damaged and denervated m. semi-tendinosus of the frog. It was shown that F-actin of denervated muscle fiber lost the ability to reply by increasing tryptophan fluorescence anisotropy during the fiber relaxation and its stretching in the rigor solution by 1--4 per cent compared to the original length. Zenker's necrosis retains this ability only slightly. It is supposed that both the denervation atrophy and Zenker's necrosis change the structure of F-actin.