Acute Hypotension. Initial: 8-12 mcg/min IV infusion; titrate to effect; Maintenance: 2-4 mcg/min IV infusion Cardiac Arrest. Initial: 8-12 mcg/min IV infusion; titrate to effect; Maintenance: 2-4 mcg/min IV infusion

Human umbilical vein endothelial cell line (ECV-304, Shanghai Institute of Cell Biology, Chinese Academy of Science) were used for activity evaluation. Cells were conventionally cultured with modified alpha-MEM containing 10% fetal bovine serum Before all the manipulation experiments, the ECV-304 (VECs) were shifted to serum-free medium (normal medium) and then divided into three groups as follows. Control group was cultured in normal medium in which 0 mol/L NE (Norepinephrine) was detecteded using the NE ELISA kit. NE+Inhibitor group was cultured in normal medium added with 10^-7 mol/L NE (Harcest Pharmaceutical CO,. Shanghai, China) and NE blocker Amitriptyline hydrochloride (10-6 mol/L). NE+Isotype group was cultured in normal medium added with 10^-7 mol/L NE (Norepinephrine) and a negative isotype of NE blocker Amitriptyline hydrochloride. The dose of NE utilized in the experiments was determined in advance through titration. It was selected to approximate the normal concentration in vivo. After 24 h of culture, the supernatant from each group was collected to measure SDF-1 using an ELISA kit (Human CXCL12/SDF-1 alpha Quantikine ELISA Kit; R&D Systems, USA) according to the manufacturer’s protocol. Similarly, the cells from the cell culture were collected for Western blotting analysis. First, proteins were extracted from the cells using the M-PER mammalian protein extraction reagent (Thermo Fisher Scientific, Hudson, USA). Then, the proteins were resolved on a NuPAGE gel and transferred to nylon membranes. After blocking with 7% fat-free dry milk for 2 h, the membranes were incubated with polyclonal rabbit anti-human SDF-1, JNK or p-JNK antibodies (1:200; Santa Cruz) at 4C overnight. After incubation with horseradish peroxidase-conjugated IgG (Santa Cruz) for 1 h, the membranes were treated with chemiluminescent substrate (Thermo) to visualize the protein bands.