Protective effects of DEX on lung injury depend on α2-adrenergic receptors. (A) Tissue sections and (B) pathological damage scores of the lung tissue stained with hematoxylin and eosin in IIR + NS, IIR + DEX and IIR + DEX + ATI groups. Magnification, ×40. (C) Western blotting of Nrf2/HO-1 expression in different groups. (D) Quantified western blotting results. Expression levels of (E) SOD and (F) MDA in the lung of different groups. Expression levels of (G) MPO, (H) IL-1β and (I) TNF-α in the lungs of different groups. ##P<0.01 vs. IIR + NS group; *P<0.05 vs. IIR + DEX group; **P<0.01 vs. IIR + DEX group. IIR, intestinal ischemia reperfusion; DEX, dexmedetomidine; NS, normal saline; ATI; Nrf2, nuclear factor-erythroid 2 related factor 2; HO-1, heme oxygenase 1; MPO, myeloperoxidase; SOD, superoxide dismutase; MDA, malondialdehyde; IL-1β, interleukin-1β; TNF-α, tumor necrosis factor-α.