Endothelial surface ultrastructure following hypoxia and hyperoxia.

Effects of hypoxia and hyperoxia on the ultrastructure of aortic endothelial cells were studied in rats. Rats were subjected to FIO2 0.05, 0.06 or 0.1 for various period times. Hypoxia was followed by nuclei protrusion, appearance of holes through the luminal membranes of individual cells. Some cells showed signs of partial of total disintegration. Hyperoxia (FIO2 = 1.0) were followed by slight morphological changes notable after 8 hours but most pronounced after 24 hours. The present study corroborated previous studies in that both hypoxia and hyperoxia can alter endothelial integrity.