ObjectiveTo explore effect of α-adrenoceptor on modulating water of lung in severe acute pancrea-titis (SAP) rat. MethodsThe SD rats were randomly divided into sham operation group (n=5) and SAP group,the SAP group was divided into subgroups of SAP-4 h (n=5) and SAP-24 h (n=5).SAP model was made by injecting taurocholate into bilopancreatic duct.The wet-to-dry ratio,alveolar fluid clearance (AFC),and AFC affected by α1-adrenoceptor inhibitor-prazosin and α2-adrenoceptor inhibitor-yohimbine separately or together were measured in the lungs.The α1-adrenoceptor and α2-adrenoceptor mRNA expressions in the lungs tissues were measured by real-time PCR. Results① The wet-to-dry ratios in the SAP-4 h group and SAP-24 h group were obviously decreased as compared with the sham operation group (P<0.05),which in the SAP-24 h group was significantly lower than that in the SAP-4 h group (P<0.05).② The AFCs in the SAP-4 h group and SAP-24 h group were obviously increased as compared with the sham operation group (P<0.05).The AFCs in the SAP with α1-adrenoceptor inhibitor-prazosin or α2-adrenocpetor inhibitor-yohimbine or prazosin combined with yohimbine were all obviously decreased as compared with the SAP group (P<0.05).③ The α1 adrenoceptor and α2 adrenoceptor mRNAs in the SAP-4 h group and SAP-24 h group were obviously increased as compared with the sham operation group (P<0.05). ConclusionAFC might be modulated by α-adrenoceptor in SAP rat.