[Effect of emotional stress on the myocardial ultrastructure of rats occupying different hierarchical ranks in a group].

Effect of immobilization stress on myocardial ultrastructure has been studied in rats occupying, according to the behavior, dominant, subdominant and "outcast" position in the group. The greatest changes are revealed in the myocardium of the dominant rats. This is explained by the fact, that mechanisms ensuring realization of certain functional systems in these animals require maximal energetic and emotional expenditure. And as the result--compensatory ability of their physiological function is lower than in animals of other ranks.