Abstract
Atherosclerosis is the most common cause of ischemic heart disease and cerebrovascular disorders. However, the mechanism of the development of atherosclerosis has not yet been fully elucidated. The object of the present study was to observe the differences in the architectural damage in the coronary and cerebral atherosclerosis regarding changes in the cellular and intercellular matrices of man. Both the intima, and media were studied. The left anterior-descending coronary arteries were obtained from 97 cases that had undergone an autopsy. Quantitative analyses were done for the following 3 parts of specimens: 1) Intima with a thickening in cases without atheroma, 2) Intima with a thickening of parts with no atheromatous changes in cases with atheroma, 3) Intima with atheromotous changes. In all materials, the number of smooth muscle cells (SMC), and the amount of elastin (EL), collagen (CL), glycosaminoglycans (GAGs) and PAS-positive materials (PAS) were estimated by using a microspectrophotometer.
The following histological differences were also observed in two arteries. In a coronary artery, the intimal thickening was diffuse and circumferential and some elastic fibers were estranged from the intimal elastic lamina; while in the cerebral artery, intimal thickening was localized in some portions and the internal elastic lamina remained thick while showing no destruction. With the progress of arterial sclerosis, the degenerated elastin, GAGS and CL (type I) increased both arteries. The PAS-positive material decreased in coronary arteries and increased in cerebral arteries, thereby suggesting the reduction of glycoproteins in the former and the production of CL (type V) in the latter. The connective tissues in the intima with the atheromatous changes was denser. in the cerebral arteries than in the coronary arteries.
