[Scanning (SEM) and transmission (TEM) electron microscopic studies on post-ischemic endothelial lesions following...

The vessel wall endothelial surface was studied after recirculation for various periods following a transitory hypoxia. The acute changes consisted of a partial or total destruction of the endothelium in certain areas. Later on the regeneration (division and process formation) of endothelial cells took place to cover the damage areas. These events were demonstrated by both transmission and scanning electron microscopy. In case of severe vessel damaged also the subendothelial matrix, the collagen- and elastic fibres as well as the stomata were set free. Blood cells anchored to these areas were also overgrown later by endothelium. The restitution was practically complete in 10 days when only some small endothelial processes had shown the previous regenerative activity. In spite of the extensive damages to the endothelium no occluding thrombus-formation was seen. The phagocytes functioned only in removing debris and the thrombocytes in facilitating endothelial overgroth.