Endothelial pavement patterns in human arteries.

The endothelium of the carotid arteries, pulmonary trunk and aorta from twelve human subjects aged between 42 and 86 yr was examined en face after staining of the cell borders with a silver nitrate solution. The three vessels each showed similar features with a background pattern of fusiform, mononuclear cells oriented in the longitudinal axis of the vessel. Superimposed on this was a highly variable pattern of small and large polygonal cells and, less commonly, giant cells. Many examples of an abrupt transition from one pattern to another were observed. Preparations which were also stained with haematoxylin showed that large polygonal cells and giant cells contained many nuclei, often arranged into one or more nuclear clusters. The endothelial pattern was related to the underlying intimal structure by taking transverse sections of selected arterial segments. Although a specific endothelial pattern could not be related to a particular intimal morphology, there was a tendency for increasing intimal fibrous thickening and lipid deposition to be associated with more disorganised endothelial patterns and with the presence of large, multinucleate endothelial cells.