Coronary arteritis in mice after systemic injection of bacterial cell wall peptidoglycan

We examined cell wall peptidoglycan (PGL) derived from group A streptococcus and other bacteria for possible induction of coronary arteritis in mouse strains. The histological finding of the main trunk of the coronary arteries of BALB/c, DBA/1J, C57BL/6 and DBA/2 mice, which were given an intravenous injection of sonicated PGL fragments of st. pyogenes at 500 micrograms per mouse 4 times at intervals of 1 week, showed diffuse cellular infiltration in the vascular wall as well as perivascular space. Marked hyperplasia of the endothelial cells was noted and necrosis of the medial smooth muscle of the coronary artery also was observed. The elastica stain clearly demonstrated fragmentation and degeneration of the elastic fibers. The histological change of the originating site of the aorta also noted swelling or hyperplasia of the endothelial cells and perivascular cellular infiltration. PGL fragments of st. mutans, st. sanguis and s. aureus did not cause any heart lesions. Coronary arteritis induced by st. pyogenes PGL could be very useful as an experimental animal model of Kawasaki's disease.