Immunohistochemical Studies of Isoimmune Myocarditis in Rabbits

ABSTRACT

The myocardial lesions by the injections of isologous heart emulsion were produced in rabbits, and organspecific isoimmune mechanism in the genesis of myocardial lesions was studied by fluorescent antibody technique and demonstration of antibodies against isologous heart muslce. Four groups of rabbits were subjected to normal untreated control, adjuvant control, injection of isologous heart homogenate aIone and injection of heart homogenate plus Freund's adjuvant. Injection of isologous heart homogenate produced circulating anti-heart muscle antibodies which were enhanced by addition of Freund's adjuvant in heart homogenate. Histologic lesions in the heart consisted of interstitial edema, mononuclear cell infiltration, degeneration of myofibers and stromal reaction. Fluorescent antibody technique on myocardial lesions showed presence of anti-heart antibodies in parallel with the degree of myocardial lesions as well as with titre of circulating antibodies. Skeletal muscle and other organs showed neither histologic alteration nor precence of anti-heart antibodies. These data clear1y indicated that the lesion in the myocardium produced by isologous heart homogenate was developed by organ-specific isoimmune reaction.