Abstract:

BACKGROUND: Studies show that, the body inevitably will be injured to different degrees upon the rapid access to high altitude, among them damage to heart and lung is apparent.
OBJECTIVE: To evaluate the influence of hypoxic acclimatization on the ultrastructure of rat heart and lung.
METHODS: SD rats were randomly divided into 4 groups, namely the plateau hypoxia 1, 3, 30 days, and a control group. The hypoxic groups of rats were brought from the Xi'an (elevation 5 m), to Golmud, Qinghai (elevation 2 700 m; 1 day), to the Naqu (elevation 4 500 m; time-consuming 3 and 30 days). The cardiopulmonary specimens were observed for the histological changes.
RESULTS AND CONCLUSION: At acute hypoxia 1 and 3 days, the microstructure and ultrastructure of lung tissues exhibited apparent interstitial pulmonary edema and alveolar pulmonary edema; rat ventricular myocytes showed varying degrees of cloudy swelling, vacuolar degeneration, necrosis and interstitial dissolved edema by the heart tissue observations under light microscopy; electron microscope displayed that, the mitochondria swelling, sarcoplasmic reticulum, myofibril dissolution, intracellular and extracellular edema in cardiac muscle cells. These changes in the right ventricular wall at hypoxia 3 days were more apparent compared with those in left ventricular wall. The interstitial edema after hypoxic acclimatization was significantly reduced at 30 days. High altitude acute hypoxia may induce pulmonary interstitial edema and alveolar pulmonary edema, as well as right ventricular-based heart damage. The heart and lung tissue lesions significantly reduced after high altitude hypoxic acclimatization.