Relationship between permeability and endothelial cell morphology in rat aortae

The permeability and endothelial cell morphology in rat aortae were measured. Using FITC-albumin as a tracer, the permeability was measured on the lateral sides of ascending aorta (immediately before the brachiocephalic artery, A), aortic arch (immediately after the left subclavian artery, C) and thoracic aorta (E), and on their medial sides, B, D and F, respectively. By silver staining endothelial cell morphology was observed in the same portions where the permeability was measured. The permeabilities in A and B of the ascending aorta were higher than those of the aortic arch and thoracic aorta. The cell morphology in A and B was almost the same as in other portions. However, the deviation values of the cell orientation to the axis of the blood vessel in A and B were higher than those in other portions. These results indicate that a complex blood flow in the ascending aorta affected the orientation of endothelial cells and might induce the changes in the permeability through endothelial cells.