[Histopathological changes of lung and right ventricle induced by high concentration of carbon dioxide in rats].
摘要
OBJECTIVE: To evaluate if high concentration of carbon dioxide causes any histopathological changes of the lung and right ventricle in rats. METHODS: Wistar rats were divided into control group (Group A, n = 21) and hypercapnic group (Group B, n = 30). Group B received mixed gas exposure (8% CO(2), 21% O(2), 71% N(2)), 7 hours daily for 4 weeks. Arterial blood gas, superoxide dismutase (SOD), lipid peroxide (LPO) in the tissue of the lung and right ventricle were determined. Histopathological changes of the lung and right ventricle were investigated by light microscope, transmission and scanning electron microscope. RESULTS: Decompensated respiratory acidosis [pH 7.21 +/- 0.04, PaCO(2) (56 +/- 3) mm Hg] developed in Group B. SOD in the lung [(463 +/- 174) U/g protein] and ventricle tissue [(235 +/- 94) U/g protein] in Group B were significantly lower than those in Group A (P < 0.01), while LPOs [(8.1 +/- 3.2) nmol/ml and (17 +/- 5) nmol/ml] in group B were significantly higher than those in Group A (P < 0.01). The index of pulmonary capillary permeability in Group B (37 +/- 4) was also higher than that in Group A (28 +/- 4, P < 0.001). Tissue edema in the lung and heart, endothelial cell damage of the small blood vessels and severe myofibril damage of the right ventricle, pulmonary microthrombus formation and increased pulmonary capillary permeability were found in Group B. CONCLUSION: Hypercapnic rat model is successfully reproduced by exposure of 8% CO(2); high concentration of CO(2) causes severe damage of the lung and right ventricle as well as the whole body.