Theresearch Of Tetramethylpyrazine's Influence On Aquaporin 1?5 In Acuterespiratory Disease Syndrome

ObjectiveAquaporins were some kinds of cell membrane proteins associated with fluid balance and there have been abundant evidence showing that aquaporins played a important role in the transportation of ARDS's lung fluid.AQP1 and AQP5 were responsible for this process together.Tetramethylpyrazine were the effective constituent of ligustrazine being verified with efficient potency of mitigating pulmonary edema,but this activity correlating with the AQP1 and AQP5's expressions whether or not were doubtful till now.In order to confirm the hypothesis,we established the ARDS model in vitro and vivo to observe the change of pulmonary edema after using tetramethylpyrazine and preliminarily investigate the regulation effects of tetramethylpyrazine on aquaporin1 and aquaporin5 in ARDS.MethodsWe builded the ARDS model in vitro and vivo,the A549 cells and healthy male SPF grade SD rats were randomly divided into the normal control group(group N),the TMP intervention group(group T),the LPS stimulation group(group L)and the TMP treatment group(LT group),then the proliferation of A549 cells was determined by MTT assay.The expressions of AQP1,AQP5 mRNA in each group cells were detected by RT-qPCR.The verification of the valid ARDS model was performed by observing the rats' general conditions and determining the arterial blood gas analysis.Moreover wet/dry ratio(W/D)of the lung tissue and hematoxylin-eosin(HE)staining was performed to observe the situation of pulmonary edema.Quantitative Real-time PCR(RT-qPCR)was used to detect the AQP1 and AQP5 mRNA level of the lung tissue homogenate,in addition Immunohistochemistry and Western blot detected the protein expressions of AQP1 and AQP5 in the lung tissue.ResultsAfter the MTT assay determining the effect of LPS and TMP on A549 cells proliferation,their optimum dosages were confirmed at 5-10mg/L and 10-50mg/L respectively.ARDS model were effective established by giving LPS(10mg/kg)through tail vein injection,meanwhile the average W/D ratio and the morphologyof lung tissue showed the pulmonary edema mitigation in LT group compared with the group L.The results of RT-qPCR showed that the level of AQP1 and AQP5 mRNA in group T was higher than those in group N and the level in group L was down-regulated;meanwhile the level in group LT was higher than this in group L(P<0.05).The results of Immunohistochemistry and Western blot were consistent with those of qRT-PCR(P<0.05).ConclusionsTMP can exhibit positive protective effects by mitigating LPS-induced pulmonary edema in ARDS effectively,and the mechanism may be associated with the upregulation of the expressions of AQP1 and AQP5.AQP1 and AQP5 may be the potential therapeutic targets of ARDS.