Abstract: Pathological changes of pulmonary small artery endothelial cells and pulmonary capillary endothelial cells under hypoxia were observed morphologically by opticalmicroscope and electromicroscope respectively, and LDH activity of pulmonary small artery endothelial under hypoxia was analyzed by histochemical staining image. Injure changes resulted from acute hypoxia, LDH activity of pulmonary small artery endothelial in groups after hypoxia was lower than that in groups before hypoxia and decreased progressively with hypoxia time. Acute hypoxia may injury vascular endothelial cells and the injury aggravates with hypoxia time, the extent to which the vascular endothelial cell is injuried is closely related to the LDH activity of it.

Key words: acute hypoxia, vascular endothelial cell, lactic dehydrogenase