Influence of autophagy on rat acute lung injury induced by lipopolysaccharide / 重庆医学

ABSTRACT

Objective To explore the influence of autophagy on lipopolysaccharide (LPS) induced acute lung injury (ALI) . Methods Forty‐eight Sprague Dawley (SD) rats were randomly divided into four groups ,12 cases in each group(1)normal saline control group (NS) ,(2)LPS model group (L) ,(3) LPS and autophagy group (L +A) and (4) LPS and autophagy inhibition group (L+I) .Arterial blood samples was obtained for detecting the blood gas ,including PaO2 ,PaCO2 and pH ,and the lung tissue dry/wet ratio was calculated .The HE staining was used to observe the histopathological changes of lung tissue .Moreover the lung le‐sion score was performed ;the expression of microtubule associated protein ,light chain protein 3b(LC3b) ,myeloperoxidase(MPO) , macrophage inflammatory protein 2(MIP‐2) ,interleukin‐1β(IL‐1β) and tumor necrosis factor‐α(TNF‐α) in serum and bronchoalve‐olar lavage fluid(BALF) was assessed by ELISA .Results Compared with the NS group ,arterial blood PaO2 and pH in the group L were decreased and PaCO2 was increased (P<0 .05);compared with the L group ,the arterial blood PaO2 and pH in the L+A group were increased and PaCO2 was declined (P<0 .01) ,the arterial blood PaO2 and pH in the L+ I group were decreased and PaCO2 was elevated ,the differences were statistically significant (P<0 .01) .The LC3b concentration in serum and BALF in the L group and L+I group was declined ,while MPO ,MIP‐2 ,IL‐1βand TNF‐αconcentrations were increased ,while which in the L+ A group were just the opposite .Conclusion Autophagy plays a improvement and protective effect on LPS induced acute lung injure in rat .