Abstract
The appearance of the human aortic wall and coronary arterial wall was examined by Scanning (SEM), Transmission electron microscopy (TEM) and chemical analysis in order to clarify the mechanism of removal of lipids deposited in the aorta.
The findings of SEM and TEM showed that circulating liucocytes penetrated into the arterial wall through endotherial marginal folds in the early atherosclerotic lesion. In some specimens many spherical bodies with a diameter of 10-30μ were observed in the subendotherial space and intimal media. After the leucocytes had phagotized a large quantity of the lipids in the arterial wall, they were transformed into lipid-including cells, which we named “lipid-containers.” Furthermore, we found that some lipid-containers returned from the subendotherial space into the blood stream. Possibly, many lipids in the atherosclerotic lesion can be removed by this process. From those new findings, it is considered that the leucocytes (macrophage) play an important role in regression and prevention of atherosclerosis of human arteries at the cellular level. The human arterial wall was divided into three sections such as intima, intimal media and media by cryostat.
The small lipids particles in the macrophages were isolated by ultracentrifugation after the three sections were digested with proteolytic enzymes. The lipid particles isolated from intima were small in diameter and very low density (1.006). But those from media were big and high density (1.210). The latter could not be so easily removed from arterial wall.
From above findings, it suggested that mobility of macrophages played an important role of lipids deposition in the arterial wall.
