Dynamics of development of autoimmune myocarditis in rats

The development of autoimmune myocarditis in rats after a single subcutaneous injection of rat myosin mixed with a complete Freund’s adjuvant (CFA) (400 μg/kg in 200 μl) was studied. The rats from the control group were injected with only CFA. The titer of antibodies to myosin, infiltration of lymphocytes into the myocardium, ultrastructural damage of myofibrils, mitochondria, and nuclei of cardiomyocytes were maximally pronounced on days 14–21 after the immunization with myosin, which indicates a peak of the inflammatory reaction. The content of nitrites and nitrates in the blood serum and myocardium of immunized rats were also studied. A certain contribution to the development of the inflammation is made by CFA: in rats injected with only CFA, morphological signs of myocarditis were found, but to a much lesser degree than in the group immunized with myosin.