THE CHANGES AND CLINICAL SIGNIFICANCE OF AQUAPORIN 5 AND CC16 IN LUNG TISSUE OF NEONATAL RATS WITH ACUTE LUNG INJURY

Objective To discuss Aquaporin 5(AQP5)and CC16 change and clinical significance in early stage of acute lung injury in neonatal rats. Methods One hundred and forty newborn rats were randomized into two group(every group n=70),subgroup rats were randomized into normal saline pretreated group(NS group) and LPS group.Lung injury models in neonatal rats were established via intraperitoneal injection of 5 mg/kg lipopolysaccharides(LPS),The pathological changes were observed under microscopy,Wet/dry ratio of lung were examined.The expression of AQP5 was examined by Western Blot.Clara cell secretory protein(CC16) in serum and BALF was detected using enzyme-linked immunoadsordent assay(ELISA). Results ① Half-hour following LPS administration to neonatal rats,lung hemorrage was observed,these changes aggravated with time after LPS administration.Wet/dry ratio in neonatal rats at 2~4 hours after LPS were significantly increased,p0.01,then decreased.② 0.5 hour after injecting LPS,AQP5 level of lung began descending,it became the lowest after 1~2 hours,Significant differences were observed in AQP5 between the NS and LPS pretreated groups(p0.01).then the level became escalate and approached normal at 8 hours,aquaporin-5 level went down again to 24 hours(p0.01).③The contents of CC16 in BALF were significant lower after the injection of LPS,Significant differences were observed in the contents of CC16 in BALF between the NS and LPS pretreated groups(p0.01).The contents of CC16 in serum were higher level compared to NS group(p0.01),In LPS groups CC16 expression peaked at 4 h,8 and16 hours decreased. Conclusion ① The change of AQP5 reflect damage in type I epithelial cells.The dynamic changes of CC16 showed the Clara cells and the integrity of alveolar epithelium and vascular endothelial cell injury.These three is a sensitive marker reflecting in early stage of ALI.② The pront of time is difference in AQP5、CC16 in BALF and serum.In orther to early discover and intervent ALI,it is preferably to monitor the former two.③ Expresstion of AQP5 suggests therapeutic window period.