Effects of A3 adenosine receptor antagonist on lung injury after cardiopulmonary bypass in rabbits / 上海交通大学学报（医学版）

ABSTRACT

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.