Protective Effects of Erythropoietin towards Acute Lung Injuries in Rats with Sepsis and Its Related Mechanisms.

The aim of this study was to explore the effects of erythropoietin (EPO) in acute lung injuries in rats with sepsis. 127 male SD rats were divided into 3 groups (n=8): group Sham, group ALI (sepsis-caused lung injury), group EPO (EPO intervention). The blood gas analysis, C-reactive protein level (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-10 were detected and compared. The water content fraction and myeloperoxidase (MPO) activities, apoptosis, and expression level of nuclear factor -κB (NF-κB p65) in lung tissues were also detected. Compared to group Sham, the oxygenation index of group ALI was decreased (140.66±12.82 vs. 194.7±16.36), CRP (peak value: 2.31±0.33 mg/L vs. 1.00±0.16 mg/L), IL-10 (peak value: 711.26±84.97 ng/L vs. 51.21±11.45 ng/L), TNF-a (63.69±6.85 ng/L vs. 12.92±0.91 ng/L), and IL-6 (peak value: 1768.93±195.11 ng/L vs. 68.71±11.48 ng/L) increased (<0.01), and the lung cell apoptosis and expression of NF-κB p65 (302.75±51.38 vs. 121.46±11.79) were also increased (<0.01), and there was a recovery of EPO group (<0.01). Group ALI exhibited pulmonary interstitial and alveolar edema, hemorrhage, and lung collapse, but the EPO intervention significantly reduced the above lung pathological changes (the water content was 70.36±1.24% in Sham group, 84.26±3.07% in ALI group and 75.72±1.96% in EPO group, <0.01; MPO: 2.23±0.67, 7.56±1.02, 5.73±0.86, <0.01; apoptotic index: 3.73±0.39, 25.69±4.54, 9.59±2.59, <0.01). EPO could inhibit the expression of NF-κB in lung tissues, inhibit the levels of proinflammatory cytokines TNF-a and IL-6, but improve the level of anti-inflammatory cytokine IL-10, thus reducing the pathological changes of lung tissues and producing protective effects towards lung tissues.