槲皮素对缺血再灌注大鼠离体心脏的作用

Effect of quercetin during ischemia-reperfusion injury on islated perfused rat hearts

目的观察槲皮素（Quercetin）对缺血再灌注损伤（IRI）离体大鼠心脏的作用。方法将32只SD大鼠随机分为4组：空白对照组（Control）；给药对照组（Control＋Que）；缺血再灌注组（I／R）；缺血再灌注给药组（I／R＋Que），行Langendorff心脏灌注，给药组预防性给予槲皮素（5μmol／L）。监测各组心功能（4-ap／dtmax），比较再灌注1h心肌尼克酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX2）、一氧化氮合酶（iNOS、eNOS）表达和超微结构的变化。结果I／R组与Control组比较心功能显著降低（分别为18．91±3．38、-22．43±8．84和60．65±11．65、-56．62±8．49，P〈0．01），NOX2、iNOS、eNOSmRNA（分另0为0．1590±0．0539、0．0897±0．0236、0．0154±0．0061和0．0247±0．0070、0．0377±0．0135、0．0091±0．0033，P〈0．05）和蛋白的表达均显著增加，心肌超微结构严重损伤；与I／R比较I／R＋Que组（45．77±8．05，-42．10±8．71）显著增强心功能（P〈0．01），显著降低NOX2、iNOS、eNOSmRNA（分另0为0．0864±0．0358、0．0445±0．0104、0．0085±0．0032，P〈0．05）和蛋白的表达，明显减轻心肌超微结构的损伤。结论在离体水平预防性给予槲皮素能够显著减轻缺血再灌注对大鼠心肌造成的损伤，保护心脏。

Objective To observe the effect of quercetin （Que） on isolated rat hearts after ischemia-reperfusion injury （IRI）. Methods Thirty-two SD rats were divided randomly into 4 groups with 8 in each group ： （ 1 ） Control group, isolated hearts contiuosly perfused without ischemia; （2） Control ± Que group： isolated hearts contiuosly perfused without ischemia but the adminstration of Que （5 μmol/L） 5 min after perfusion; （3） I/R group： isolated hearts perfused with 30 min global ischemia followed by reperfusion; （4） I/R ± Que group： isolated hearts perfused with 30 min global ischemia followed by reperfusion and the adminstration of Que （5 μmol/L） 10 min before ischemia. Hemodynamic parameters （ ± dp/dtmax）, myocardial ultrastructure, nicotinamide adenine dinucleotide phosphate （NADPH） oxidases 2 （NOX2）, inducible nitric oxide synthase （iNOS） and endothelial nitric oxide synthase （eNOS） mRNA and protein expression after reperfusion were compared among the four groups. Results As compared with control group, hemodynamic parameters were greatly decreased after reperfusion （18.91 ± 3.38, -22. 43 ± 8.84 vs 60. 65 ± 11.65, - 56. 62 ± 8.49 ,P 〈 0. 01 ）, myocardial ultrastructures were significantly destroyed and the expression levels of NOX2, iNOS, eNOS mRNA and protein were significantly increased after 60-min reperfusion （0. 1590 ± 0. 0539, 0. 0897 ± 0. 0236, 0. 0154 ± 0. 0061 vs 0. 0247 ± 0. 0070, 0. 0377 ± 0. 0135, 0. 0091 ±0. 0033 ,P 〈0. 05） in I/R group. As compared with I/R group, hemodynamic parameters were significantly recovered （45.77 ± 8. 05, - 42. 10 ± 8. 71, P 〈 0.01 ）, myocardial ultrastructures were well protected and the expression levels of NOX2, iNOS, eNOS were significantly decreased （0. 0864 ±0. 0358, 0. 0445 ±0. 0104, 0. 0085 ±0. 0032,P 〈0.05） in I/R ± Que group, but there was no significant difference between control group and control ± Que group （ P 〉 0. 05 ）. Conclusion Que can protect isolated perfused rat hearts from IRI by its antioxidative effect.