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.