目的观察双侧迷走神经切除对大鼠肺缺血再灌注损伤(LIRI)导致的炎症反应的影响。方法 SD大鼠24只,随机分为假手术组(S组)、缺血再灌注组(IR组)和双侧迷走神经切断合并缺血再灌注组(NIR组),每组8只。于缺血前、再灌注0.5h及再灌注4h抽取动脉血进行血气分析,观察动脉血氧分压(Pa O2)及肺泡动脉氧分压差(A-a DO2)的变化。实验结束时取左肺测量肺组织的湿/干重比(W/D),于光学显微镜下观察缺血再灌注后肺的病理学改变,采用ELISA检测肺组织匀浆中肿瘤坏死因子-α(TNF-α)、白细胞介素-10(IL-10)含量及髓过氧化物酶(MPO)活性等炎性指标的水平。结果与S组比较,IR组Pa O2明显降低,A-a DO2明显升高,W/D及肺组织匀浆中TNF-α、IL-10含量和MPO活性明显增加,肺组织炎性细胞浸润、肺泡腔红细胞增多、肺泡破坏及组织水肿明显(P〈0.05)。与IR组相比,NIR组Pa O2进一步降低,肺组织炎性反应及病理学损伤更加严重(P〈0.05),但A-a DO2无明显变化。结论切断双侧迷走神经可加重大鼠肺缺血再灌注损伤,提示迷走神经完整性在LIRI的炎性反应调节中具有重要作用。
Objective To explore the effect of bilateral vagal ner ves transection on the inflammator y reaction of rats induced by lung ischemia and reperfusion. Methods Twenty-four adult male SD rats weighed 250-320 g were randomly divided into 3 groups(8 each): Sham group(S group), ischemia reperfusion group(IR group) and bilateral vagal ner ves transaction and ischemia-reperfusion group(NIR group). Blood gas analysis with arterial blood was performed to detect the arterial partial pressure of oxygen(Pa O2) and arterial-alveolar oxygen pressure gradient(A-a DO2) before ischemia and 0.5 and 4 hours after reperfusion. At the end of the experiment, the left lung tissues were collected to measure wet/dry ratio, the pathological changes were observed by light microscopy, and inflammatory indicators, including tumor necrosis factor-α(TNF-α), interleukin-10(IL-10) levels and myeloperoxidase(MPO) activity were detected. Results Compared with S group, ischemia and reperfusion injury sharply decreased Pa O2 and increased A-a DO2; the MPO activity, the contents of TNF-α and IL-10 and the wet/dry ratio obviously increased in IR group; more infiltration of inflammatory cells, hemorrhage, thickening and swelling of alveolar walls were observed. Compared with IR group, PaO_2 further decreased while A-a DO2 had no obvious change in NIR group, the inflammatory reaction and pathologic lesions in lung tissues were getting worse. Conclusion Bilateral vagal nerves transaction may aggravate lung ischemia and reperfusion injury, suggesting that the integrity of vagal nerves play a significant role in regulating inflammatory reaction of lung ischemia and reperfusion injury in rats.