Abstract: 【Abstract】Objective To observe the expression change of inflammatory factors systemically and locally in lung tissue in mice with renal ischemia-reperfusion injury, and to understand the role of inflammatory response in renal ischemia-reperfusion injury related acute lung injury. Methods Thirty male C57BL/6 mice were randomly divided into control group (sham operation group, n=10), ischemia-reperfusion group (I/R group, n=10), or acute uremia group by bilateral nephrectomy (BNx group, n=10). After the operations for 6 or 24 h, mice were sacrificed, and serum, lung and kidney tissues were collected. Pathological changes in kidney and lung were examined after H-E staining, and the number of infiltrated neutrophils was evaluated. The wet/dry ratio of lung was obtained by weighing wet lung and dried lung. Protein concentration in bronchoalveolar lavage (BAL) was measured by BCA method. The concentrations of IL-6, IL-1β and TNF-α in serum and BAL were assayed by ELISA. IL-6, IL-1β and TNF-α mRNAs in lung were quantified by realtime quantitative PCR. IL-6, IL-1β and TNF-α in lung were also detected by immunohistochemistry. Result In I/R and BNx groups, urea nitrogen (BUN) and Scr increased significantly after the operation for 24 h, as compared with those in sham group (P＜0.05). In I/R and BNx groups after the operation, lung tissues showed that infiltration of inflammatory cells, capillary hemorrhage around alveoli, interstitial edema, andneutrophil number were higher than those in sham group (P＜0.05). In I/R, BNx and sham groups after the operation for 6 h, serum IL-6 was 606.32±59.07, 300.22±169.73 and 121.52±9.12 pg/ml, respectively; serum IL-1β was 443.93±91.98, 959.47±184.46 and 21.71±2.47 pg/ml, respectively; serum TNF-α was 119.67±21.66, 132.33±62.64 and 30.21±2.46 pg/ml, respectively. These cytokines in serum were significantly higher in I/R and BNx groups than in sham group (P＜0.05). In I/R, BNx and sham groups after the operation for 6 h, BAL IL-6 was 109.74±15.91, 70.00±2.42 and 37.69±7.96 pg/mg, respectively; BAL IL- 1β was 117.02±27.46, 215.35±18.49 and 42.10±5.20 pg/mg, respectively; BAL TNF-α was 512.31 ±71.95, 988.25±133.55 and 52.76±12.82 pg/mg, respectively. These cytokines in BAL were significantly higher in I/R and BNx groups than in sham group (P＜0.05). In I/R and BNx groups after the operation for 6 h, IL-6, IL-1β and TNF-α mRNAs in lung increased significantly. Immunohistochemistry for IL-6, IL-1β and TNF-α in lung demonstrated the similar results. Conclusion Renal ischemia-reperfusion injury may mediate acute lung injury. The increase of inflammation factors in lung and serum may involve in the renal ischemia-reperfusion injury related lung injury.

Key words: Ischemic reperfusion injury, Acute kidney injury , Acute lung injury, Inflammatory factor, Mechanism