全流量体外循环对大鼠心肌损伤和神经功能的影响

The influence produced by a full-flow extracorporeal circulation model on myocardial injury and neurological function in rats

目的利用建立的全流量大鼠体外循环(ECC)模型,研究ECC灌注对大鼠心肌损伤和神经功能的影响。方法16只雄性Sprague-Dawley大鼠在完成尾动脉、腹壁尾侧浅动、静脉和右侧颈外静脉血管穿刺置管后,随机分为ECC组和对照组。ECC组在此基础之上建立ECC并进行灌注90min,而对照组仅进行等长时间的麻醉下机械通气。所有动物均进行血气和血液动力学等基本生理指标监测并在ECC前、ECC后60min以及ECC后1周测定细胞因子[白介素(IL)-6和IL-10]、心肌损伤指标[心肌肌钙蛋白I(cTnI)和心型脂肪酸结合蛋白(HFABP)]和心脏功能。在ECC后第3d、5d和7d分别对两组大鼠进行神经功能评分。结果所有实验动物全部存活,ECC组成功建立全流量ECC。外科操作也可以诱导大鼠出现明显的炎症反应,而ECC则进一步加重了这种反应。外科操作与ECC均造成cTnI明显增高,但是两组之间在ECC后60min没有统计学意义(P>0.05);HFABPECC组在ECC后60min要明显比对照组高(P<0.05)。两组实验动物的收缩和舒张功能随着时间变化不明显,但是ECC组大鼠的舒张功能在ECC后60min要低于对照组(P<0.05)。两组动物在术后都存在一定程度的神经学功能障碍并随着时间有逐渐恢复的趋势,但ECC组大鼠在术后第3d、5d和7d的神经功能障碍严重程度要明显要高于对照组(P<0.05)。结论本实验的全流量大鼠ECC模型成功地模拟了临床相关实践,ECC导致实验大鼠出现了炎性反应、心肌损伤、心脏功能障碍及神经功能障碍。

OBJECTIVE Utilizing the successfully established full -flow extracorpereal circulation （ECC） model in rats to investigate potential influences on myocardial injury and neurological function. METHODS Sixteen male Sprague - Dawley rats were randomly divided into two groups- ECC group and Control group, after tail arteries, superficial caudal epigastria arteries and veins, and right jugular veins were cannulated. Ninety minutes extracorporeal Circulation was performed on the ECC group; ventilation under general anesthesia was offered to control group. Blood gas analysis and basic physiological values were monitored. Plasma cytokines （IL - 6 and IL- 10）, myocardium injury biomarkers （cTnI and HFABP） and cardiac function were measured before ECC, 60 minutes after ECC and 1 week after ECC. A neurological scoring system was used to evaluate the neurological function in both groups at 3 d, 5 d, and 7 d postoperatively. RESULTS ECC was successfully established and all subjects were recovered from surgery and ECC. Signifi- cant inflammation was induced by surgery but further aggravated by ECC. cTnI was elevated by both surgery and ECC but no statistic difference was found between ECC group and control group. Based on HFABP, myocardial injury in ECC rats at sixty minute after ECC was more significant than in control group. Changes of systolic and diastolic cardiac function with time were not observed but at sixty miantes after ECC the diastolic function in ECC group were reduced compared with in control group. Neurological function, which was more severe compromised in ECC group compared to control at 3 d, 5 d, and 7d postoperatively, was injured in both control and ECC group after operation, but a recovery tendency was also presented. CONCLUSION This full - flow ECC model in rats successfully mimicked clinical practice, and inflammation, myocardial injury, myocardial dysfunction and neurological dysfunction were induced by ECC.