恩氟烷对多柔比星致大鼠心肌损伤及p38MAPK信号通路的影响

Effects of Enflurane on Doxorubicin-induced Myocardial Injury and p38MAPK Signal Pathway in Rats

目的:探究恩氟烷(ENF)对多柔比星(DOX)致大鼠心肌损伤及p38丝裂原活化蛋白激酶(p38MAPK)信号通路的影响。方法:将72只大鼠随机分为对照组(Control组)、DOX组、ENF低(ENF-L,1%)、中(ENF-M,2%)、高剂量组(ENF-H,3%)、SB组(p38MAPK抑制剂SB2035801.5 mg·kg^(-1)),每组12只。采用尾静脉注射DOX(4 mg·kg^(-1))制备心肌损伤大鼠模型。药物组大鼠吸入相应剂量的药物2h。停止吸入后超声心电图检查大鼠心脏功能;生化法检测血清肌酸激酶同工酶MB(CKMB)、肌钙蛋白I(cTnI)、乳酸脱氢酶(LDH)水平和心肌匀浆中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)水平;HE染色观察心脏组织形态变化;流式细胞术检测心肌细胞凋亡;荧光探针测定心肌中活性氧(ROS)水平;Western blot检测心肌组织p38MAPK通路和凋亡相关蛋白B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关X蛋白(Bax)、半胱氨酸天冬氨酸蛋白水解酶3(Caspase-3)的表达。结果:与Control组相比,DOX组大鼠的左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、血清CKMB、cTnI、LDH、心肌MDA水平、心肌细胞凋亡率、ROS水平、p-p38MAPK/p38MAPK、Bax、Caspase-3表达等指标均显著升高(P<0.05),左心室射血分数(LVEF)和左心室短轴缩短率(LVFS)、心肌SOD、GSH-Px、Bcl-2表达等指标则显著下降(P<0.05),心肌损伤严重;与DOX组相比,SB组和ENF-M、ENF-H组大鼠的LVESV、LVEDV、血清CKMB、cTnI、LDH、心肌MDA、细胞凋亡率、ROS水平、p-p38MAPK/p38MAPK、Bax、Caspase-3表达明显下降(P<0.05),LVEF、LVFS、心肌SOD、GSH-Px、Bcl-2的表达明显升高(P<0.05);心肌损伤明显减轻。结论:恩氟烷对多柔比星诱导的心肌损伤有保护作用,其作用可能与抑制p38MAPK通路的激活,改善心肌细胞线粒体氧化损伤,抑制细胞凋亡有关。

Objective:To explore the effects of enflurane(ENF)on doxorubicin(DOX)-induced myocardial injury and p38 mitogen-activated protein kinase(p38 MAPK)signaling pathway in rats.Methods:Seventy-two rats were randomly divided into control group,DOX group,low-(ENF-L,1%),medium-(ENF-M,2%)and high-dose(ENF-H,3%)enflurane groups,and SB group(p38 MAPK inhibitor SB203580,1.5 mg·kg^(-1))with twelve mice in each group.A rat model of myocardial injury was prepared by injecting DOX(4 mg·kg^(-1))into tail vein.The rats in the drug groups inhaled the corresponding dose of drug for 2 h.After the inhalation,the rat’s heart function was checked by echocardiography;the serum levels of creatine kinase isoenzyme MB(CKMB),troponin I(cTnI)and lactate dehydrogenase(LDH),and the levels of malondialdehyde(MDA),superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)in myocardial homogenate were detected by biochemical methods;the morphological changes of heart tissue were observed by HE staining;cardiomyocyte apoptosis was detected by flow cytometry;the level of reactive oxygen species(ROS)in myocardium was measured by fluorescence probe;the myocardial tissue p38 MAPK pathway and apoptosis-related protein B-cell lymphoma-2(Bcl-2),Bcl-2 associated X protein(Bax)and cysteine aspartate proteolytic enzyme 3(Caspase-3)expressions were detected by Western blot.Results:Compared with those in the control group,the left ventricular end diastolic volume(LVEDV),left ventricular end systolic volume(LVESV),serum CKMB,cTnI and LDH,myocardial MDA level,myocardial cell apoptosis rate,ROS level,and p-p38 MAPK/p38 MAPK,Bax and Caspase-3 expressions of rats in DOX group increased significantly(P<0.05),left ventricular ejection fraction(LVEF),left ventricular short axis shortening rate(LVFS),myocardial SOD and GSH-Px and Bcl-2 expressions decreased significantly(P<0.05),and myocardial injury was severe;compared with those in DOX group,the LVESV,LVEDV,serum CKMB,cTnI and LDH,myocardial MDA,apoptosis rate,ROS level,and p-p38 MAPK/p38 MAPK,Bax and Caspase-3 expressions decreased significantly(P<0.05),LVEF,LVFS,myocardial SOD and GSH-Px,and Bcl-2 expression increased significantly(P<0.05),and myocardial injury was significantly reduced.Conclusion:ENF has a protective effect on DOX-induced myocardial injury,and its effect may be related to inhibiting the activation of p38 MAPK pathway,improving the oxidative damage of cardiomyocyte mitochondria and inhibiting the cell apoptosis.