Relations between disturbances in microcirculation and accumulation of lipids in the aortic wall.

For the purpose of unraveling the relations between disturbances in microcirculation and deposition of lipids in the aortic wall, 9 rabbits were fed a 1% cholesterol and 5% coconut oil at intervals up to 16 weeks, and 4 rabbits were used as controls. After microangiography of vasa vasorum, the same specimens were studied histochemically. The distribution of vasa vasorum became poorer on sacrifice by microangiography. However, it could not be thought that disturbances in vasa vasorum was a cause in the early deposition of lipids, because lesions were histologically mild in the greater parts of vasa vasorum. The sites of prediction for the vascular lesions were initially the branching part, and then the thoracic aorta. Thickness and numbers of the elastic lamina in the media decreased straightly in the distal direction, and the degree of intimal thickening and accumulation of lipids were parallel with the degree of the medial thickness. The intimal cells tended to be arranged radially with wide intercellular spaces in the cross section, suggesting the convenience for the passage of fluids. From the above facts, it may be reasonable to presume that the difference in severity of disturbances of microcirculation resulted in the difference in the site of predilection.