[The effect of antioxidant treatment in pneumonia of granulocytopenic rats].

OBJECTIVE

To evaluate the therapeutic role of antioxidant intervention in granulocytopenia rats with pseudomonas aeruginosa pneumonia.

METHODS

90 male Sprague-Dawley rats were randomly divided into two groups. Group A: the control granulocytopenia group, in which the granulocytopenia was induced by using cyclophosphamide and cortisone acetate. Group B: the antioxidant intervention group, in which the granulocytopenia model was the same as group A, while peritoneal injection of NAC 150 mg.kg(-1).d(-1) half an hour after the immunocompromised model was reproduced, and the injection was continued for a consecutive 7 days, and NAC was injected once more half an hour before bacterial tracheal inoculation. The model of pulmonary infection was established by using standard a strain of pseudomonas aeruginosa. The time-course of the following was observed 0 h before bacterial inoculation, and 6 h, 9 h, 24 h, 48 h and 72 h after infection: the peripheral white blood cells, mortality, oxidant/antioxidant indexes, bacterial burden of lung tissue homogenate, pulmonary vascular permeability and lung wet/dry weight ratio, and the pulmonary histopathological changes.

RESULTS

The peripheral white blood cells of both groups were less than 4 x 10(9)/L. The concentration of superoxide dismutase in both serum and lung tissue in group B were higher than that in group A, while concentration of malondialdehyde in group B was lower than that in group A. Pulmonary vascular permeability and lung wet/dry ratio of group B were much lower than that of group A. There was no difference in bacterial burden of lung tissue between the two groups. Group B showed a lower mortality than group A (16.3% vs 23.4%). Lung histopathological observation showed that lung injury, pulmonary congestion and hemorrhage were more serious or obvious in group A as compared with group B. Apoptotic bodies were found in the lung epithelial cells of Group A.

CONCLUSIONS

Antioxidant intervention can alleviate lung injury in the granulocytopenia rats with pseudomonas aeruginosa pneumonia. It may become an important subsidiary approach to pneumonia in granulocytopenia patients.