A scanning electron microscopic (SEM) study on the endothelium of the normal rabbit aorta.

In scanning electron microscopic (SEM) studies the appearance of the normal endothelial surface of the rabbit thoracic aorta was considered. The intercellular bridges described by other authors as elements of the normal endothelial surface were interpreted as artifacts in this study. In silver stained preparations the endothelial cells appeared as oblong rhombic fields depicted by sinuous silver lines and with their long axes forming acute angles with the coarse longitudinal folds produced by the first elastic lamella. The endothelial surface was smooth, the nuclei were faintly visible and in unstained specimens cell boundaries were not clearly demarcated. Artifacts probably produced by fixation, dehydration, air drying and coating were frequent, appearing as shrinkage, tissue rupture and curling up of the cells.