Histological structure of bovine coronary arteries at varying distance from their origins from the aorta (a preliminary study).

Coronary arteries of three bovine hearts, obtained from animals, aged about 2 years, were studied. Both right and left coronary arteries were dissected out, divided into 10 mm long segments, fixed in formalin and embedded in paraffin. Histological sections were cut in a plane perpendicular to the axis of the vessel and stained, using van Gieson's method; additional staining with resorcin-fuchsin. We observed a distinct thickening of the tunica media, formed by circular layers of smooth muscle cells and by a small amount of elastic fibres, in the ramus interventricularis subsinuosus and paraconalis. The tunica media thickenings were situated in the middle segments of the coronary arteries at a distance of about 2-3 cm from its origin in the aorta.