INDUCTION OF CARDIAC LESIONS, CLOSELY RESEMBLING THOSE OF RHEUMATIC FEVER, IN RABBITS FOLLOWING REPEATED SKIN INFECTIONS WITH GROUP A STREPTOCOCCI

Abstract

Cardiac lesions, closely resembling those found in rheumatic fever in man, have developed in a small portion of rabbits that have sickened after multiple, successive skin infections with several serological types of "M"-rich group A streptococci. The rabbit cardiac lesions are found in valves, valve sulci and rings, mural endocardium, epicardium, coronary arteries and arterioles, and in myocardial interstitium, unrelated to arteries or veins but often to capillaries. Many of the rabbit cardiac granulomata occurring in blood vessel adventitia and para-adventitia and in the myocardial interstitium bear striking resemblance to Aschoff bodies. A striking increase in size of the adrenal glands occurred in the rabbits dying, or sacrificed while sick following the last strepto-coccal skin infection. Microscopically hyperplasia, hypertrophy, and necrosis of fascicular zone cells are seen. There appears to be direct correlation between the degree of macroscopic enlargement of the fascicular zone of the adrenal cortex and the occurrence of the myocardial granulomata.