高胆固醇血症共病心肌缺血/再灌注损伤大鼠模型的建立

Establishment of rat models of myocardial ischemia/reperfusion injury with hypercholesterolemic comorbidity

目的构建高胆固醇血症共病心肌缺血/再灌注损伤(ischemia/reperfusion injury,IRI)大鼠模型。方法SD大鼠20只,随机分为正常组10只和高胆固醇血症组10只,高胆固醇血症组采用含质量分数2%胆固醇和质量分数0.5%胆盐的饲料喂养8周,正常组采用基础饲料喂养8周。比较正常组与高胆固醇血症组大鼠喂养前与喂养8周时体质量及喂养8周时血清总胆固醇、三酰甘油、低密度脂蛋白胆固醇水平。正常组再分为正常对照组5只和IRI组5只,高胆固醇血症组再分为高胆固醇血症对照组5只和高胆固醇血症-IRI组5只,采用免疫抑制法检测大鼠血清肌酸激酶同工酶-MB(creatine kinase isoenzyme-MB,CK-MB)水平,采用速率法检测大鼠血清乳酸脱氢酶(lactate dehydrogenase,LDH)和心肌肌钙蛋白I(cardiac troponin I,cTnI)水平,采用伊文氏蓝和2,3,5-氯化三苯基四氮唑双重染色法测定大鼠心肌梗死面积。结果喂养8周时,正常组和高胆固醇血症组大鼠体质量[(417.00±22.13)、(420.25±21.23)g]均高于喂养前[(138.40±4.88)、(139.60±4.12)g](P<0.05);喂养前和喂养8周时,2组大鼠体质量比较差异均无统计学意义(P>0.05)。喂养8周时,高胆固醇血症组大鼠血清总胆固醇[(3.80±0.51)mmol/L]、低密度脂蛋白胆固醇[(0.84±0.22)mmol/L]水平均高于正常组[(2.00±0.29)、(0.37±0.12)mmol/L](P<0.05),三酰甘油水平[(1.52±0.37)mmol/L]与正常组[(1.47±0.33)mmol/L]比较差异无统计学意义(P>0.05)。高胆固醇血症-IRI组大鼠血清LDH[(3141.50±492.34)u/L]、CK-MB[(2618.80±82.16)u/L]、cTnI[(1.16±0.17)μg/L]水平均高于正常对照组[(416.40±46.40)u/L、(211.20±55.20)u/L、(0.14±0.03)μg/L]、IRI组[(1465.40±319.59)u/L、(1509.40±232.42)u/L、(0.75±0.08)μg/L]和高胆固醇血症对照组[(612.60±50.80)u/L、(420.10±90.60)u/L、(0.24±0.04)μg/L](P<0.05),IRI组均高于正常对照组和高胆固醇血症对照组(P<0.05);高胆固醇血症对照组大鼠血清CK-MB和cTnI水平均高于正常对照组(P<0.05),LDH水平与正常对照组比较差异无统计学意义(P>0.05)。正常对照组和高胆固醇血症对照组大鼠无心肌梗死,高胆固醇血症-IRI组大鼠心肌梗死面积[(64.34±3.39)%]大于IRI组[(51.74±3.47)%](P<0.05)。结论成功构建高胆固醇血症共病心肌IRI大鼠模型,高胆固醇血症可明显加重心肌IRI。

Objective To establish the rat models of myocardial ischemia/reperfusion injury(IRI)with hypercholesterolemic comorbidity.Methods Twenty SD rats were randomly and equally divided into normal group and hypercholesterolemia group.The rats in hypercholesterolemia group were fed with a diet containing 2%cholesterol and 0.5%bile salt for 8 weeks,while the rats in normal group received normal diet.The body mass before and after 8 weeks of feeding,and the serum levels of total cholesterol,triacylglycerol and low-density lipoprotein cholesterol after 8 weeks of feeding were compared between two groups.Normal group was equally redivided into normal control group and IRI group,while hypercholesterolemia group was equally redivided into hypercholesterolemia-control group and hypercholesterolemia-IRI group.The serum level of creatine kinase-MB(CK-MB)was detected by immunosuppressive assay.The serum levels of lactate dehydrogenase(LDH)and cardiac troponin I(cTnI)were detected by rate method.The myocardial infarct size was measured by Evans blue and 2,3,5-triphenyltetrazolium chloride staining method.Results The body masses were greater after 8 weeks of feeding((417.00±22.13),(423.50±20.94)g)than those before feeding((138.40±4.88),(139.60±4.12)g)in both normal and hypercholesterolemia groups(P<0.05),and showed no significant differences between two groups both before and after feeding(P>0.05).After feeding for 8 weeks,the levels of serum total cholesterol and low-density lipoprotein cholesterol were higher in hypercholesterolemia group((3.80±0.51),(0.84±0.22)mmol/L)than those in normal group((2.00±0.29),(0.37±0.12)mmol/L)(P<0.05),and there was no significant difference in triacylglycerol level between hypercholesterolemia group((1.52±0.37)mmol/L)and normal group((1.47±0.33)mmol/L)(P>0.05).The levels of LDH,CK-MB and cTnI were higher in hypercholesterolemia-IRI group((3141.50±492.34)u/L,(2618.80±82.16)u/L,(1.16±0.17)μg/L)than those in normal control group((416.40±46.40)u/L,(211.20±55.20)u/L,(0.14±0.03)μg/L),IRI group((1465.40±319.59)u/L,(1509.40±232.42)u/L,(0.75±0.08)μg/L)and hypercholesterolemia-control group((612.60±50.80)u/L,(420.10±90.60)u/L,(0.24±0.04)μg/L)(P<0.05),and higher in IRI group than those in normal control group and hypercholesterolemia-control group(P<0.05).The levels of CK-MB and cTnI were higher in hypercholesterolemia-control group than those in normal control group(P<0.05),and there was no significant difference in LDH level between two groups(P>0.05).No myocardial infarction was observed in normal control group and hypercholesterolemia-control group.The myocardial infarct size was larger in hypercholesterolemia-IRI group((64.34±3.39)%)than that in IRI group((51.74±3.47)%)(P<0.05).Conclusion The rat models of myocardial IRI with hypercholesterolemic comorbidity are successfully established,and hypercholesterolemia would significantly aggravate myocardial IRI.