摘要
目的探讨大鼠心肌缺血再灌注损伤(MIRI)前、后使用脂氧素A4(LXA4)对心肌组织Na^+-K^+-ATP酶的影响及意义。方法72只SD大鼠随机分成假手术一组(C1组)、假手术二组(C2组)、MIRI一组(I/R1组)、MIRI二组(I/R2组)、MIRI前用药组(LX,组)、MIRI后用药组(LX2组),每组12只。建立大鼠MIRI模型,各组于开胸前取血(T1)、实验结束后取血(T2)测血清cTnI浓度。检测Na^+-K^+-ATP酶蛋白、mRNA的表达及活性改变;同时检测心肌细胞凋亡率,测定SOD活性、MDA含量,电镜下观察各组超微结构的改变。结果I/R1、LX1与C1相比,I/R2、LX2与C2相比,Na^+-K^+-ATP酶蛋白(α1:0.19±0.03,0.29±0.05比0.46±0.06,0.21±0.03,0.36±0.05比0.48±0.07,α2:0.20±0.02,0.32±0.04比0.54±0.05,0.23±0.03,0.38±0.04比0.56±0.06,α3:0.24±0.03,0.35±0.04比0.61±0.04,0.26±0.03,0.4l±0.04比0.59±o.04,β1:0.22±o.03,0.33±0.04比0.56±0.04,0.24±0.03,0.39±0.04比0.54±0.04),mRNA的表达下降[(0.21±0.07)×10^6,(0.55±0.28)×10^6比(5.73±1.97)×10^6,(0.20±0.09)×10^6,(1.78±0.86)×10^6比(6.21±2.22)×10^6],活性(mmol/gprot)降低(0.73±0.04,0.95±0.11比1.38±0.15,0.75±0.04,1.19±0.12比1.37±0.13);血清cTnI浓度(ng/L)(T2)(580.93±43.92,292.95±21.99比151.53±14.00,592.80±60.83,207.13±28.54比155.18±14.92),凋亡指数(52.52±6.36,34.55±5.65比7.48±2.09,54.75±6.29,26.53±4.60比8.54±2.76)以及SOD活性(U/mgprot)(196.84±31.82,293.59±43.10比102.55±24.77,202.48±35.40,411.71±60.44比113.36±26.95)、MDA含量(nmol/gprot)(2402.94±438.56,1548.57±238.08比472.48±190.77,2422.28±517.74,1055.48±237.44比483.26±172.05)显著增高(P〈0.05)。LX1与I/R1,LX2与I/R2相比,Na^+-K^+-ATP酶蛋白(α1:0.29±0.05比(0.19±0.03,0.36±0.05比0.21±0.03,0.2:0.32±0.04比0.20±0.02,0.38±0.04比(0.23±0.03,α3:0.35±0.04比0.24±0.03,0.41±0.04比0.26±0.03,β1:0.33±0.04比0.22±0.03,0.39±0.04比0.24±0.03)、mRNA的表达[(0.55±0.28)×10^6比(0.21±0.07)×10^6,(1.78±0.86)×10^6,比(0.20±0.09)×10^6]明显增加,Na^+-K^+-ATP酶活性(mmol/gprot)(0.95±0.11比0.73±0.04,1.19±0.12比0.75±0.04)与SOD的活性(U/mgprot)(293.59±43.10比196.84±31.82,411.7l±60.44比202.48±35.40)明显增强;同时凋亡指数(34.55±5.65比52.52±6.36,26.53±4.60比54.75±6.29)、血清cTnI浓度(ng/L)(T2)(292.95±21.99比580.93±43.92,207.13±28.54±592.80±60.83)、MDA含量(nmol/gprot)(1548.57±238.08比2402.94±438.56,1055.48±237.44比2422.28±517.74)也明显降低(P〈0.05)。LX气对缺血再灌注后心肌超微结构有明显的保护作用。结论在MIRI前、后应用LXA4能明显减轻心肌氧化损伤,上调Na^+-K^+-ATP酶蛋白、mRNA的表达,增强Na^+-K^+-ATP酶的活性,保护心肌超微结构,减少细胞凋亡,发挥其心肌保护作用。
Objective To investigate the influence and significance of LipoxinA4 (LXA4) on myocardial Na+ -K+ -ATP enzyme in rats undergoing ischemia reperfusion injury. Methods Seventy- two SD rats were randomly divided into six groups (n = 12) : sham operation group one (group C1 ) sham operation group two (group Ca); MIRI group one (group I/R1 ); MIRI group two (group I/ R2 ) ; pre-MIRI treatment group one (group LX1 ) ; post-MIRI treatment group two (group LX2 ). The rat model of MINI was established, the serum cTnI concentrations were measured in each group before chest opening (T1) and at the end of the experiment (T2). The expression and activity change of Na+-K+ -ATP enzyme protein, mRNA were detected. At the same time, myocardial cell apoptosis was detected with TUNEL method, the SOD activation and MDA content were checked, while the ultrastructural changes of cardiac muscle were observed under electron microscope. Results In group I/R1, LX1 (compared with group C1 ) and group I/R2, LX2 (compared with group C2 ), the expression levels of Na+ -K+ -ATP protein (α1: 0. 19 ± 0. 03, 0. 29 ± 0. 05 to 0. 46 ± 0. 06, 0. 21 ± 0. 03,0. 36 ± 0.05 to 0. 48 ± 0. 07 , α2 : 0. 20 ± 0. 02 , 0. 32 ± 0. 04 to 0.54±0.05,0.23±0.03,0.38±0.04 to 0.56± 0. 06,α3:0. 24 ± 0. 03,0. 35 ± 0. 04 to 0. 61 ± 0. 04,0. 26 ± 0. 03,0. 41 ± 0. 04 to 0. 59 ± 0. 04,β1:0. 22 ± 0. 03,0. 33 ± 0. 04 to 0. 56 ± 0. 04,0. 24 ± 0. 03,0. 39 ± 0. 04 to 0. 54 ± 0. 04) and mRNA( (0. 21 ± 0. 07) ×10^6,(0.55±0.28)×110to (5.73±1.97) ×10^6,(0.20±0.09) ×10^6,(1.78±0.86) ×10^6 to (6.21 ± 2. 22) ×10^6 ). The activities of Na± -K± -ATP (mmol/gprot) were decreased respectively. Serum cTnI concentrations (T2), the apoptotic index and SOD activation (U/mgprot), MDA content(nmol/ gprot) all increased significantly (P〈0. 05). In group LX1 (compared with group I/R1 ) and group LX2 (compared with group I/R2 ), the expression of Na+ -K+ -ATP protein, mRNA and activity of Na+-K+-ATP (mmol/gprot), SOD(U/mgprot) were raised significantly, while the serum cTnI concentrations ( T2 ) ( ng/L), MDA content (nmol/gprot) and apoptotic index were decreased significantly (P〈0. 05). LXA4 had obvious protective effect on myocardial uhrastructure after ischemia reperfusion. Cenelusions Before and after MIRI, application of LXA4 could significantly attenuate myocardial oxidative injury, upregulate the expression of Na+ -K+ -ATP protein and mRNA, enhance the activity of Na+ -K+ -ATP enzyme. LXA4 plays its role in myocardial protection via the protection of myocardial uhrastructure and reduced apoptosis.
出处
《中华小儿外科杂志》
CSCD
北大核心
2013年第11期848-853,共6页
Chinese Journal of Pediatric Surgery
基金
浙江省教育厅科研计划项目,浙江省外科学重中之重学科开放基金资助,浙江省卫生厅重点支撑学科-小儿外科学基金