Effects Of Intermedin1-53with SP-A And IL-18on Acute Lung Injury Of LPS-induced Septic Rats

Objective To explore the influence of intermedinl-53on the leve of SP-A in BALF and IL-18expressions of alveolar monocyte-macrophage cell inlipopolysaccharide of LPS-induced acute lung injury (ALI) in rats.Methods36male Wistar rats were randomly divided into3groups:normal control (A),LPS-treated group (B), intermediary1-53intervention group (C). each group of12. the intraperitoneal injection of normal saline1ml,1h after intravenous injection of normal saline1ml, ALI group of normal saline1ml,1h after intravenous injection of LPS5mg/kg (dissolved in1ml saline), C group of the intraperitoneal injection IMD1-532nmol/kg (dissolved in1ml saline),1h after intravenous injection of LPS5mg/kg (dissolved in lml saline). Blood samp leswere taken for blood gas analysis (PO2) at2,4h,. The animals were killed, the ratio of wet to dry lung weight was measured, The concentration of SP-A in BALF with ELISA method,The exression of IL-18was examined by immunohistochemical method and the changes of lung tissue were pathologically observed.Results1.compared with group A, PO2and had a decreased significantly in2and4hours in group B (P<0.01), IMD1-53intervention after each phase PO2were significantly higher (P <0.01).2. Group B at all time points lung W/D ratio was significantly higher than group A (P <0.01); IMD1-53intervention is the ratio of reduced (P<0.05, P<0.01), Group C at each time point the mean of the group A high,2h point difference compared to a significant (P<0.01),4h point, the difference was not significant (P>0.05).3. Group B Specimens visible lung tissue swelling, scattered bleeding points; observed under light microscope to see the alveolar septum was obviously enlarged, the destruction of the integrity of the alveolar wall, lung tissue inflammatory cell infiltration, alveolar space red blood cells and monocyte-macrophage cell exudation, localhyaline membrane formation, with focal atelectasis and emphysema. With the extension of the course, severity and gradually increase the phase group C, group lesions than those in group B the corresponding phase group to reduce.4. Compared with group A at each time point, group B BALF of SP-A concentration decreased significantly (P<0.01) in group C compared with group B at each time point, the SP-A concentration was significantly higher (P <0.05, P<0.01).5. Immunohistochemical results showed:IL-18, the absorbance A of the group B was at all time points measured lung mononuclear macrophages was significantly increased (P <0.05, P<0.01), IMD1-53after the intervention, group C IL-18absorbance decreased significantly (P<0.05, P<0.01).Conclusion The intermediary1-53through inhibide the decreased of SP-A and expression of in the early stage of acute lung injury has a protactive function.