CONTACT GUIDANCE IN THE SUB-ENDOTHELIAL SPACE - REPAIR OF RAT AORTA INVITRO

The regeneration of cells was observed on the surface of pieces of rat aorta partially denuded of endothelium and grown for several days in organ culture. Persisting endothelial cells did not contribute significantly to the population of cells that covered the denuded area; these were principally very enlongated smooth muscle cells. Except where the aorta had been transected, they were invariably parallel to the original long axis of the aorta. Similarly, chick embryo cells and Earle's L strain fibroblasts assumed a longitudinal orientation when seeded from suspension cultures onto devitalized, bare subendothelium. Scanning electron microscopic observation of the exposed subendothelium showed a longitudinal fibrillary pattern. The longitudinal orientation of cells on the subendothelium in organ cultures is thought to be comparable to that seen during the repair of arteries in situ, when longitudinal smooth muscle cells form layers under the endothelium. It is considered to be caused by contact guidance provided by the fibrillary structures of the subendothelial space. © 1979.