[Histopathological changes of lung and right ventricle induced by high concentration of carbon dioxide in rats].
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.


CONCLUSIONS
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.
Wang
J
J
Department of Pulmonary Medicine, Beijing Chaoyang Hospital Affiliated to Capital University of Medical Science, Beijing Institute of Respiratory Disease, Beijing 100020, China.
Wang
C
C
Pang
B
B
D000818:Animals; D002245:Carbon Dioxide / Q000009:adverse effects*; D006352:Heart Ventricles / Q000293:injuries / Q000473:pathology* / Q000648:ultrastructure; D008168:Lung / Q000473:pathology* / Q000648:ultrastructure; D055370:Lung Injury; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D002245:Carbon Dioxide