[Role of injury in the appearance of "activated" smooth muscle cells].

The ultrastructure of the smooth muscle tissue was studied in the posterior vena cava in rats after the disturbance of blood outflow, in the stomach following resection of half of its fundus and cecum after constriction of its ascending limb. "Activation" of the smooth muscle was found to reflect the stage of the cell ultrastructure injury, and then the processes of intracellular regeneration. Analysis of the correlation between the DNP-synthesizing and the "activated" cells showed the latter to be of local origin, from the differentiated myocytes.