右美托咪啶对老龄大鼠离体心肌缺血再灌注损伤影响

Effects of Dexmedetomidine on Vitro Aged Rat Heart of Ischaemia Reperfusion Injury

为研究通过右美托咪啶预处理对老龄大鼠离体心肌缺血再灌注损伤的影响,选择40只健康老龄雄性SD 老龄大鼠,体重250~300g,随机分为4 组,建立Langendorff 模型.I-R 组：继续灌注K-H 液30min;DEX-K-H1组：继续灌注含0.2ng.mL-1右美托咪啶的K-H液20min;DEX-K-H2组：继续灌注含2ng.mL-1右美托咪啶的K-H液20min;DEX-K-H-Y组：继续灌注含2ng.mL-1右美托咪啶和1M育亨宾的K-H液20min.DEX-K-H1 组、DEX-K-H2 组、DEX-K-H-Y 组于20min 后冲洗10min K-H 平衡液.各组造成全心缺血的方式均为停灌30min,然后再灌注120min K-H 平衡液.记录各组缺血前、平衡灌注末、再灌注60min、再灌注120min的心率（HR）、左心室形成压（LVDP）、左室内压上升最大速率（＋dp∕dtmax）、左室内压下降最大速率（-dp∕dtmax）.于再灌注末测定超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量.结果表明：缺血后各组HR无显著差异（p〉0.05）,与IR 组、DEX-K-H-Y 组相比,DEXK-H1 组、DEX-K-H2 组各时点的垣dp∕dtmax、-dp/dtmax、SOD 增加,MDA 下降（p〈0.05 或p〈0.01）,且DEX-K-H-Y 组变化最明显.说明右美托咪啶预处理对老龄大鼠缺血再灌注心脏的心功能有所改善,具有一定的保护老龄大鼠心肌缺血再灌注损伤作用,右美托咪啶的浓度影响其保护心肌效果.

Effects of Dexmedetomidine on vitro aged rat heart of ischaemia reperfusion injury were studied. Male old aged SDrats were selected, and the Langendorff model were successfully prepared, then were randomly divided into 4 groups ofequilibration （n=10 earch）. I-R group： the hearts after 10 min stabilization were perfused for 30min; For DEX-K-H1 group, thehearts were perfused with dexmedetomidine （0.2ng.mL-1） and K-H solution for 20min, then before ischemia conduct wash way for10min; For DEX-K-H2 group, the hearts were perfused for 20min with 2ng.mL-1 dexmedetomidine and K-H solution, then beforeischemia conduct wash way for 10min; DEX-K-H-Y group： the hearts were perfused for 20min with 2ng.mL-1 dexmedetomidine andK-H solution and 1滋M yohmbine, then before ischemia conduct wash way for 10min; The precedure of conducting hearts ischemiawas subjected for 30min, then followed reperfusion with K-H solution for 120min. HR, LVDP, ＋dp∕dtmax and -dp∕dtmax at thetime of ischemia beginning, the time of the balance end and the time of 60min, the time of 120min reperfusion duration wererecorded. The content of MDA and the activity of SOD in the myocardium at the reperfusion end were measured. The resultsshowed there were no statistical significance of HR in four groups （p 〉0.05） after ischemia,the ＋dp∕dtmax, -dp∕dtmax, SOD ingroup DEX-K-H1 and group DEX-K-H2 were higher in the group of DEX-K-H-Y and IR, MDA in group DEX-K-H1 andgroup DEX-K-H2 were lower in the group of DEX-K-H-Y and IR （p〈0.05 or p〈0.01）. The change of group of DEX-K-H-Ywas significant. Dexmedetomidine has a protective effect on vitro heart of aged rat.