Endothelial Surface of Rabbit Aorta as Observed by Scanning Electron Microscopy

Abstract

Scanning electron microscope observation of the ascending aorta and arcus aortae of rabbits revealed that the endothelial surface possessed a number of hair-like projections of about 100-150mμ thickness and of lengths up to 3μ. The processes were numerous on the nuclear swelling of the cell. Small granule-like processes were also numerous on the cell which were presumed to represent very short projections.Transmission electron microscopy of ultra-thin sections confirmed the occurrence of the endothelial surface projections.Together with the result by SMITH et al. (1971) in the dog pulmonary artery, this study may demand a fundamental revision in the understanding of the structure and function of the endothelial surface of blood vessels.