Feng Jianhua, Lucchinetti Eliana, Fischer Gregor, Zhu Min, Zaugg Kathrin, Schaub Marcus C, Zaugg Michael
Cardiovascular Anesthesia Research Laboratory, Center of Clinical Research, Institute of Anesthesiology, E-HOF, University Hospital Zurich, Rämistrasse 100, Zurich CH-8091, Switzerland.
Cardiovasc Res. 2008 Apr 1;78(1):98-107. doi: 10.1093/cvr/cvn016. Epub 2008 Jan 24.
We tested whether delayed pharmacologic preconditioning elicited by isoflurane is protective in infarct-remodelled hearts.
Male Wistar rats were treated with the preconditioning drug isoflurane 6 weeks after permanent ligation of the left anterior descending coronary artery. Twenty-four and 48 h later, hearts were perfused on the Langendorff system and treated with cyclooxygenase-2 or 12-lipoxygenase inhibitors before exposure to 40 min of ischaemia followed by 90 min of reperfusion. Infarct size was determined by triphenyltetrazolium chloride staining and lactate dehydrogenase release. Cyclooxygenase-2 expression and activity were measured by Western blotting and colorimetric assay. Nuclear translocation of cyclooxygenase-2-inducing transcription factors HIF1alpha, CREB, STAT3, and NFkappaB was determined. Post-infarct, remodelled hearts exhibit alterations in cellular signalling, time course and extent of isoflurane-induced late protection. While remodelled, preconditioned hearts exhibited protection exclusively at 24 h, healthy hearts showed sustained protection for up to 48 h, which correlated with cyclooxygenase-2 protein expression and enzymatic activity. The cyclooxygenase-2 inhibitors celecoxib and NS-398, but not the 12-lipoxygenase inhibitor cinnamyl-3,4-dihydroxycyanocinnamate, abolished delayed protection in both healthy and remodelled hearts, identifying cyclooxygenase-2 as a key mediator of late protection in both models. Isoflurane induced nuclear translocation of HIF1alpha in all hearts, but CREB was exclusively activated in healthy but not remodelled myocardium, which expressed higher levels of the CREB antagonist ICER. Delayed protection by isoflurane in remodelled hearts was more vulnerable to inhibition by celecoxib.
Isoflurane failed to mobilize cyclooxygenase-2-inducing CREB in ICER-overexpressing, remodelled hearts, which was associated with a shortening of the second window of protection.
我们测试了异氟烷引发的延迟药理预处理对梗死重塑心脏是否具有保护作用。
雄性Wistar大鼠在左冠状动脉前降支永久性结扎6周后用预处理药物异氟烷进行处理。24小时和48小时后，在Langendorff系统上对心脏进行灌注，并在暴露于40分钟缺血然后90分钟再灌注之前用环氧化酶-2或12-脂氧合酶抑制剂进行处理。通过氯化三苯基四氮唑染色和乳酸脱氢酶释放来确定梗死面积。通过蛋白质免疫印迹法和比色测定法测量环氧化酶-2的表达和活性。确定环氧化酶-2诱导转录因子HIF1α、CREB、STAT3和NFκB的核转位。梗死后，重塑心脏在细胞信号传导、异氟烷诱导的延迟保护的时间进程和程度方面表现出改变。虽然经过重塑，但预处理的心脏仅在24小时时表现出保护作用，健康心脏则显示出长达48小时的持续保护作用，这与环氧化酶-2蛋白表达和酶活性相关。环氧化酶-2抑制剂塞来昔布和NS-398，但不是12-脂氧合酶抑制剂肉桂酰-3,4-二羟基氰基肉桂酸酯，消除了健康和重塑心脏中的延迟保护作用，确定环氧化酶-2是两种模型中延迟保护的关键介质。异氟烷在所有心脏中均诱导HIF1α的核转位，但CREB仅在健康而非重塑心肌中被激活，重塑心肌中表达较高水平的CREB拮抗剂ICER。异氟烷在重塑心脏中的延迟保护作用更容易受到塞来昔布的抑制。
在ICER过表达的重塑心脏中，异氟烷未能激活诱导环氧化酶-2的CREB，这与保护作用的第二个窗口缩短有关。
