Morphometric Analysis of Retinal Vascular Endothelial Cells in Rats

Abstract

In the present study, we observed the transformation of endothelial cells in the retinal vessel of normal rats and examined the relationship between morphometrical parameters and vessel calibers. Retinal vessels of male Wistar-Kyoto rats were stained with an en face silver staining method and the vessel caliber, the axis of the cell oriented parallel to the longitudinal axis and to the transverse plane of the vessel, and the deviation angle of endothelial cells against the vessel axis were measured under a light microscope. As the vessel caliber increased, endothelial cells showed a tendency to extend along the longitudinal axis in the arterioles, but endothelial cells remained unchanged in the venules. The deviation angle of endothelial cells was nearly parallel to the vessel axis especially in the arterioles. Change in shape of endothelial cells in the retinal arterioles suggested a high shear stress in the large arterioles, and lower shear stress in the smaller arterioles with its decrease of caliber. In the venules, however, the cell shape was unchanged, and this suggests that the blood flow is fairly steady.