Histochemical Studies of Human Coronary Atherogenesis: Comparison With Aortic And Cerebral Atherogenesis
A series of new histochemical techniques developed in our laboratory was employed in a study of human coronary arteries obtained from individuals ranging in age from fetal life to 70 years of age. Our conclusions are as follows:
No apparent relationship exists between lipid and acid mucopolysaccharides with respect to staining intensity or distribution in any of the groups studied.
The earliest morphological alteration in coronary arteries is a primary deposition of lipid. This lipid was observed within endo-thelial cells, as small subendothelial aggregates within macrophages and muscle fibers, or as extracellular deposits. The presence of lipid within the internal elastic membrane and fragmented elastic fibers was an infrequent finding.
A comparison of this study with our previous histochemical studies of aorta and cerebral atherogenesis resulted in the following conclusions: At least two independent mechanisms may be responsible for the fatty changes occurring in these arteries; (a) infiltration of lipid via the endothelium and (b) degenerative changes within elastic elements. Lipid was never found in endothelial cells and muscle fibers in cerebral arteries, and was observed only occasionally in aortas. The most frequent site of lipid in cerebral arteries was within the internal elastic membrane while lipid was rarely found in the internal elastic membrane of coronary arteries and only occasionally in aortas.
The ratio of chondroitin sulfate B to chon-droitin sulfate A or C increased with aging and severity of changes of elastic fibers in the area of the internal elastic membrane, with a concomitant increase in the ratio of coarse-to-fine collagen. It is suggested that this relationship indicates a reinforcement mechanism which strengthens the arterial wall at sites of fragmentation of the internal elastic membrane.
- Received May 22, 1963.
- © 1963 American Heart Association, Inc.