[Role and related mechanism of resolvin D1 in lung ischemia reperfusion injury in rats].

Abstract

Objective: To investigate the role and related mechanism of resolvin D1 (RvD1) in lung ischemia-reperfusion injury (LIRI) in rats. Methods: Forty male Sprague-Dawley rats, 7-8 weeks, weighing 220-280 g, were divided into 4 groups using a random number table method: sham operation group, lung ischemia reperfusion control group, normal saline group, and RvD1 group. The rat model of LIRI was produced by 45 min of occlusion of the left hilum of lungs followed by 150 min reperfusion. In sham group, no blocking of the left hilum of lung after thoracotomy; Normal saline 2 ml/kg and RvD1 100 μg/kg were injected respectively at 10 min of reperfusion in normal saline group and RvD1 group. Blood samples were collected from the femoral vein for determination of interleukin (IL)-6, tumor necrosis factor (TNF)-α, soluble inter-cell adhesion molecules (sICAM-1) concentrations at 150 min of reperfusion. The rats were sacrificed after collection of blood samples and then lung tissues were taken for observation of the pathological changes and for measurement of lung wet/dry weight ratio (W/D). The the contents of malondialdehyde (MDA), monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-2 and the activity of myeloperoxidase (MPO) in lung tissues were determined. The protein relative expression of nuclear factor (NF)-κB in lung tissues was detected by Western blot. Lung tissue cell apoptosis was detected with TUNEL method. Results: The plasma level of IL-6, TNF-α, sICAM-1 in normal saline group and RvD1 group were significantly higher than those in the Sham group [(110±7), (100±4) vs (72±3) ng/L, (151±8), (153±6) vs (104±5) ng/L, (2 690±133), (2 760±167) vs (1 953±125) ng/L]. Besides, NF-κB protein relative expression level of lung tissues up-regulated [(0.681±0.033), (0.664±0.024) vs (0.292±0.011)] (all P<0.05). The W/D, apoptosis index, MDA, MCP-1, MIP-2 contents and MPO activity in lung ischemia reperfusion control group, normal saline group and RvD1 group were significantly higher than those in the Sham group [(5.92±0.31), (5.85±0.24), (5.06±0.08) vs (4.14±0.10), (32.9±1.5)%, (31.9±1.3)%, (17.7±1.8)% vs (8.1±0.6)%, (72.1±2.3), (66.7±3.7), (34.0±1.4) vs (22.0±0.8) nmol/mg, (3.99±0.28), (3.86±0.25), (2.66±0.16) vs (1.47±0.17) pg/mg, (9.45±0.53), (9.68±0.62), (7.62±0.22) vs (4.70±0.41) pg/mg, (3.01±0.18), (2.92±0.19), (1.58±0.11) vs (0.98±0.07) U/g] (all P<0.05). The plasma levels of the cytokines mentioned above, the W/D, the apoptosis index, MDA, MCP-1, MIP-2 contents and MPO activity in RvD1 group were significantly lower than those in the lung ischemia reperfusion control group [(63±4) vs (110±7) ng/L, (90±8) vs (151±8) ng/L, (1 835±182) vs (2 690±133) ng/L, (5.06±0.08) vs (5.92±0.31), (17.7±1.8)% vs (32.9±1.5)%, (34.0±1.4) vs (72.1±2.3) nmol/mg, (2.66±0.16) vs (3.99±0.28) pg/mg, (7.62±0.22) vs (9.45±0.53) pg/mg, (1.58±0.11) vs (3.01±0.18) U/g]. Besides, NF-κB protein relative expression level of lung tissues down-regulated [(0.313±0.012) vs (0.681±0.033)] (all P<0.05). Inflammatory cell infiltration in LIRI groups increased significantly, while it was significantly reduced in RvD1 group. Conclusion: RvD1 can effectively alleviate the tissue damage caused by lung ischemia-reperfusion through down-regulating NF-κB expression, relieving inflammatory reaction and oxidative stress, reducing apoptosis in rats.