CHANGE OF CARBON MONOXIDE IN PLASMA AND TISSUE DURING ACUTE HYPOXIA

摘要

Objective. To investigate the role of endogenous carbon monoxide (CO) in hypoxia. Methods. After rats were inhaled with hypoxic gases and the heme oxygenase inhibitor ZnPPIX was administered, we measured the CO levels in plasma, liver, lung and kidney. Meanwhile plasma cGMP levels were observed. Furthermore, we recorded the changes of hemodynamic and blood gases. Results. Acute mild hypoxia (10% O_2) significantly increased CO levels in plasma as well as liver, kidney and lung, while acute severe hypoxia (5% O_2) significantly decreased CO levels in plasma as well as liver, kidney and lung. In addition, the former significantly elevated cGMP levels in plasma while the latter markedly reduced cGMP levels in plasma. The hemodynamic changes occurred in accordance with the changes of carbon monoxide. Conclusions. Our results indicate, for the first time , that the endogenous carbon monoxide plays an important role in regulating the vessel tone during hypoxia.