A COMPARISON OF CORONARY-ARTERIES FROM JAPANESE AND NZ SUBJECTS

This paper describes a comparison of the anterior descending branch of the left coronary artery from 198 Japanese subjects of ages less than 60 yrs, with 301 New Zealand individuals of similar ages. The object of the study was to determine whether there were structural difference s present which could be partially responsible for the low incidence o f atherosclerosis in Japanese as well as the known low blood lipid lev els. It was found that the internal elastic lamina of Japanese coronar y arteries was less well formed at birth than that of NZ subjects. Int imal thickening was greater in Japanese coronary arteries from birth t o the end of the first decade, but increased less rapidly with age, an d was only about half as great as that of NZ vessels in the older age groups. The thickened intima or Japanese arteries was more uniform rou nd the circumference of the vessel, the luminal surface was better for med with more stainable elastin present subjacent to the endothelial c ells, and there was less evidence of mural thrombosis. NZ arteries sho wed pronounced eccentricity of the intima, more extensive lipid deposi ts, a poorly defined luminal surface, and frequent evidence of mural t hrombosis.