[Influence of different doses of porcine pulmonary on the therapeutic effects in rats with oleic acid induced acute lung injury].

OBJECTIVE: To investigate the therapeutic effects and dose effect relationship of intratracheal instillation of different doses of porcine pulmonary surfactant (PPS) in rats with oleic acid (OA) induced acute lung injury (ALI). METHODS: Arterial blood gases and respiratory rate during the experiments, survival rate, lung index, total protein (TP) content in bronchoalveolar lavage fluid (BALF), tumor necrosis factor-alpha (TNF-alpha) level in plasma, light microscopy examination of lung specimens after the experiments were determined and performed in control group, OA (0.2 ml/kg) + saline, OA + PPS 50 mg/kg, OA+PPS 80 mg/kg, OA+PPS 100 mg/kg, OA+PPS 150 mg/kg, OA+PPS 200 mg/kg groups, respectively. RESULTS: In PPS 50 mg/kg group, arterial blood gases were improved and respiratory rate was reduced during the first 2 hours (P<0.05). Arterial blood gases and reduced breath rates respiratory rate were not improved in other PPS treatment groups but 4 hours-survival rate was lowered, lung index was decreased, protein content s in BALF and TNF-alpha level in serum were lowered, and pathological changes were ameliorated compared with group given saline after OA, especially in high dosage of PPS (150-200 mg/kg) group (P<0.05). CONCLUSION: Administration of PPS via trachea provides obvious effects on respiratory functions in rats with OA induced ALI, moreover PPS (> or =80 mg/kg) alleviates lung injury. There is no dose-effect relationship of PPS in PPS-treatment groups.