缺血再灌注对大鼠心肌损伤及氧化应激的影响

Influence of different reperfusion time on myocardial ischemic injury and oxidative stress in rats

目的探讨心肌缺血大鼠恢复血流再灌注后不同时间心肌损伤程度及氧化应激水平变化。方法 36只SD大鼠随机分为假手术组、缺血组、缺血再灌注10min组、30min组、60min组、120min组各6只。缺血组,10min组、30min组、60min组、120min组制备大鼠心肌缺血模型,假手术组不结扎冠状动脉。10min组、30min组、60min组、120min组分别于再灌注10、30、60、120min采集动脉血,缺血组不恢复血流再灌注,于缺血30min后采集动脉血,假手术组于开胸后采集动脉血,检测各组大鼠血清超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)、肌酸激酶同工酶(creatine kinase isoenzyme-MB,CK-MB)水平及乳酸脱氢酶(lactate dehydrogenase,LDH)活性,并进行比较。结果缺血组、10min组、30min组、60min组、120min组血清CK-MB[(932.29±79.80)、(1 070.25±221.70)、(822.11±67.92)、(1 030.57±153.41)、(1 173.86±169.18)u/L]、MDA[(6.96±0.82)、(7.96±0.39)、(6.56±0.81)、(6.82±0.92)、(9.34±1.11)μmol/L]均高于假手术组[(390.94±190.75)u/L、(5.07±0.96)μmol/L],LDH活性[(547.53±95.04)、(534.24±55.64)、(520.37±93.04)、(557.50±93.23)、(629.86±46.91)u/L]均高于假手术组[(404.68±77.55)u/L],SOD水平[(155.98±7.92)、(162.39±3.20)、(176.27±9.12)、(178.01±3.60)、(153.35±9.57)u/mL]均低于假手术组[(203.24±20.62)u/mL](P<0.05);30min组、缺血组、10min组、60min组、120min组血清CK-MB水平逐渐增加(P<0.05);10min组、120min组血清MDA水平高于缺血组、30min组、60min组(P<0.05),10min组与120min组、缺血组与30min组及60min组血清MDA水平比较差异无统计学意义(P>0.05);缺血组、10min组、30min组、60min组、120min组血清LDH活性及SOD水平比较差异均无统计学意义(P>0.05)。结论缺血再灌注损伤与氧化应激有关,其损伤程度在再灌注早期出现短暂减弱后又明显增强。

Objective To investigate the degree of myocardial ischemic injury and change of oxidative stress at different time after reperfusion in rats.Methods Thirty-six Sprague-Dawley rats were randomly divided into sham operation group,ischemia group,10 min group(ischemia-reperfusion for 10 min),30 min group(ischemia-reperfusion for30 min),60 min group(ischemia-reperfusion for 60 min)and 120 min group(ischemia-reperfusion for 120 min).The coronary artery was not ligated in sham operation group,and the myocardial ischemia-reperfusion model was established in the other 5 groups.Arterial blood was collected in 10,30,60 and 120 min after reperfusion respectively in 10,30,60 and 120 min groups,in 30 min after ischemia but no reperfusion in ischemia group,and after opening the chest in sham operation group to detect and compare the levels of serum superoxide dismutase(SOD),malondialdehyde(MDA)and creatine kinase isoenzyme(CK-MB)as well as the activity of lactate dehydrogenase(LDH).Results The levels of CK-MB((932.29±79.80),(1 070.25±221.70),(822.11±67.92),(1 030.57±153.41),(1 173.86±169.18)u/L)and MDA((6.96±0.82),(7.96±0.39),(6.56±0.81),(6.82±0.92),(9.34±1.11)μmol/L)as well as the activity of LDH((547.53±95.04),(534.24±55.64),(520.37±93.04),(557.50±93.23),(629.86±46.91)u/L)in ischemia,10 min,30 min,60 min and 120 min groups were significantly higher than those in sham operation group((390.94±190.75)u/L,(5.07±0.96)μmol/L,(404.68±77.55)u/L),and SOD level((155.98±7.92),(162.39±3.20),(176.27±9.12),(178.01±3.60),(153.35±9.57)u/mL)was significantly lower than that in sham operation group((203.24±20.62)u/mL)(P<0.05).The serum level of CK-MB increased gradually in 30 min,ischemia,10 min,60 min and 120 min groups(P<0.05).The MDA level was significantly higher in 10 min and 120 min groups than that in ischemia,30 min and 60 min groups(P<0.05),and there was no significant difference between 10 min group and 120 min group,as well as in ischemia group compared with 30 and 60 min groups(P>0.05).There were no significant differences in LDH activity and SOD level among ischemia,10 min,30 min,60 min and 120 min groups(P>0.05).Conclusion Ischemia-reperfusion injury is correlated with oxidative stress,and the degree of injury increases significantly after a brief weakening in the early stage of reperfusion.