A3腺苷受体激动剂预处理对兔体外循环中肺组织损伤的影响

目的 研究A3腺苷受体(A3AR)激动剂IB-MECA预处理对兔体外循环(CPB)中肺组织损伤的影响。方法 24只新西兰大白兔随机分为对照组（仅行体外循环）、激动剂组（阻断主动脉前15 min静脉注射IB-MECA）和拮抗剂+激动剂组（IB-MECA干预前15 min静脉注射选择性A3AR拮抗剂MRS-1191），每组8只。CPB结束后采集样本，分别检测和比较各组血清肿瘤坏死因子-α(TNF-α)和白介素-8(IL-8)水平、肺组织丙二醛(MDA)含量和髓过氧化物酶(MPO)活性、肺组织湿/干重比(W/D)、氧合指数(PaO2/FiO2)、肺血管阻力(PVR)和气道压(AWP)等指标，观察各组动物肺组织病理学改变。结果 CPB后，激动剂组血清TNF-α和IL-8水平显著低于对照组和拮抗剂+激动剂组 (P<0.05)；与对照组和拮抗剂+激动剂组比较，激动剂组CPB后肺组织W/D较小，MDA含量较少，MPO活性较低，组间比较差异均有统计学意义（P<0.05)；  CPB后，激动剂组PaO2/FiO2显著高于对照组和拮抗剂+激动剂组(P<0.05)，而AWP和PVR显著低于对照组和拮抗剂+激动剂组(P<0.05)；组织学观察发现，激动剂组肺组织的组织病理学改变较对照组和拮抗剂+激动剂轻微。结论 A3AR激动剂IB-MECA预处理可显著减轻CPB过程中的肺组织损伤程度。

Effects of A3 adenosine receptor antagonist on lung injury after cardiopulmonary bypass in rabbits

Objective To investigate the effects of A3 adenosine receptor ( A3AR) agonist on lung injury after cardiopulmonary bypass ( CPB) in rabbits. Methods Twenty-four rabbits were randomly divided into 3 groups, with 8 in each group. Rabbits in control group only received CPB, those in agonist group were given selective A3AR agonist IB-MECA intravenously 15 min before aorta clamp, and those in agonist + antagonist group were managed with selective A3AR receptor antagonist MRS-1191 intravenously before IB-MECA infusion. After CPB, serum concentrations of tumor necrosis factor-α ( TNF-α) and interleukin-8 ( IL-8), concentrations of malondialdehyde ( MDA) and myeloperoxidase ( MPO) in lung tissues, lung wet/dry weight ratio ( W/D), lung function related indexes of PaO_2/FiO_2, airway pressure (AWP) and pulmonary vascular resistance ( PVR), and histological changes of lung tissues were observed. Results Concentrations of serum TNF-a and IL-8 were significantly lower in agonist group than in control group and agonist + antagonist group (P <0.05). Compared with control group and agonist + antagonist group, W/D was much smaller, and concentrations of MDA and MPO were significantly lower in agonist group after CPB (P <0.05). PaO_2/FiO_2 was significantly higher, while AWP and PVR were significantly lower in agonist group than in control group and agonist + antagonist group (P <0.05). It was revealed by histological examinations that the pathological changes were less severe in agonist group than in control group and agonist + antagonist group. Conclusion A3AR agonist IB-MECA can reduce lung injury after CPB.