Effects of exogenous pulmonary surfactant on inflammatory response in rats with ventilator-induced lung injury / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of exogenous pulmonary surfactant(PS)on the inflammatory response in rats with ventilator-induced lung injury(VILI).Methods Twenty-eight adult male Wistar rats weighing 310-388 g were randomly divided into 4 groups(n =7 each)normal control group(group C),group VILI,group PS and air control group(group A).VILI was produced by high-pressure ventilation(HPV)with peak inspiratory pressure(PIP)40 cm H2 O,respiratory rate(RR)20 hpm and without positive end-expiratory pressure(PEEP)for 20 min.The rats were sacrificed by exsanguination immediately after anesthesia and after VILI in groups C and VILI,respectively.In groups PS and A,PS 100 mg/kg(50 mg/ml)and the equal volume of air were injected into the trachea via the airway after the tracheal edema fluid was removed respectively,and the rats were mechanically ventilated(Vr 10 ml/kg,RR 45 bpm and PEEP 7.5 cmH2O)for 120 min and then sacrificed by exsanguination.The blood samples were taken from femoral artery for determination of the plasma levels of IL-6,IL-10,MIP-2 and TNF-α by ELISA.The tracheal edema fluid was collected to determine the protein concentration by Bradford method.The lungs were removed for microscopic examination and the number of neutrophils was counted under microscope.Results There was no significant difference in the plasma levels of TNF-α among the four groups(P ＞ 0.05).Compared to group C,the plasma levels of MIP-2,IL-10 and IL-6 were significantly increased and the number of neutrophils was significantly enlarged in group VILI(P ＜ 0.05).The number of neutrophils was significantly smaller in group PS than in group A(P ＜ 0.05).There was no significant difference in the plasma levels of MIP-2,IL-10 and IL-6 between groups PS and A(P ＞ 0.05).The inflammatory damage in lung tissues was observed obviously in groups VILI,A and PS.Conclusion When exogenous PS is used to treat the rats with VILI,PS reduces neutrophil recruitment,but can not inhibit the release of inflammatory cytokines.