Experimental process

All rats were given free food and water and kept under standard conditions (room temperature, 22±2˚C; 12-h light/dark cycle; relative humidity, 50-60%) and left to acclimatize for 1 week. The mice were randomly assigned to the following groups: i) Sham group; ii) SAP group; iii) SAP-emodin (Emodin) group; and iv) SAP-DEX (DEX) group, with 10 rats in each group. Pentobarbital (4%; 30-40 mg/kg) was injected intraperitoneally in all rats for anesthesia. Retrograde infusion treatment of 5% sodium taurocholate (1 ml/kg; Sigma-Aldrich; Merck KGaA) into the biliary pancreatic duct was performed to induce SAP-associated ALI in the SAP, Emodin and DEX groups. Emodin (cat. no. E8390; Beijing Solarbio Science & Technology Co., Ltd.) treatment (4 mg/ml; 40 mg/kg) was administered to rats via gavage 2 h after rats gained consciousness following SAP induction, as previously described (30). DEX (Henan Lingrui Pharmaceutical Co., Ltd.) treatment (5 mg/ml; 2 ml/kg) was intraperitoneally injected at 2 h post-SAP induction in the DEX group as previously described (33). Rats were anesthetized using pentobarbital (40 mg/kg) intraperitoneally before euthanasia by exsanguination at 24 h post-modeling. Blood and lung tissues were collected and stored at 4˚C and -80˚C, respectively, for analysis.