The Effects of Azithromycin on Inflammatory Mediaters and Inflammatory Cells in Rats with Acute Lung Injury

Objective: The purpose of this study was to reproduce the model of acute lung injury(ALI)in rats by injecting oleic acid(OA)into the vein,and investigate the alterations of tumour necrosis factor-α(TNF-α and polymorphonuclear leukocyte(PMN)after ALI induced by OA,and investigate the possible mechanisms of protective effects of azithromycin in OA induced ALI in rats.Methods: OA was used to reproduce the model of ALI in rats.90 adult Sprague-Dawley rats were randomly divided into three groups:normal control group treated by saline injection(NC group),ALI group induced by oleic acid injection(OA group),therapy group treated by oral azithromycin(AZI group).Arterial oxygen tension(PaO2),arterial carbon dioxide tension(PaCO2),power of hydrogen(pH)were assayed after the animals were exsanguinated and sacrificed at 1,3 and 7 days later.The left lung was used to calculate wet/dry weight ratio(W/D)、histopathology,whereas the right lung was lavaged and determined the total proteins(TP)、TNF-α and Inflammatory cells concentration in the bronchoalveolar lavage fluid(BALF). Results: In the OA group,W/D、TNF-α、TP and Inflammatory cells in the BALF were significantly increased(P0.01),whereas the arterial oxygen tension (PaO2)were significantly decreased(P0.01)as compared with NC group.Obvious pathological manifestations such as hyperemia、edema、hemorrhage、neutrophil infiltration were shown.In the AZI group,the change of lung pathology was significantly relieved,the PaO2 were increased(P0.05),W/D、TNF-α、PMN were significantly decreased(P0.05)as compared with OA group.Conclusions: Azithromycin may prevent pulmonary microvascular leakage,improve pulmonary gas exchange ability,reduce TNF-2 and PMN,so azithromycin may lessen the development of ALI to some extent.