【摘要】 目的探讨中药单体前胡丙素(Pra-C)对缺血/再灌注(I/R)心肌细胞保护作用的机制。方法将培养的乳鼠心肌细胞随机分为I/R组、Pra-C预处理组和对照组。用全自动生化仪测定各组乳酸脱氢酶(LDH)的漏出量(n=5)。半定量RT-PCR检测钠钙交换蛋白(NCX)mRNA的转录(n=3),其活性以液闪仪测定Na+依赖的45Ca2+摄取率表示(n=5)。细胞膜钙ATP酶(PMCA)的活性以定磷比色法测定(n=5)。结果I/R组LDH的漏出量显著增加(P<0.01),Pra-C预处理组与I/R组比较LDH的漏出量显著降低(P<0.01)。I/R组NCX Na+依赖的45Ca2+摄取率比对照组显著增高(P<0.01),Pra-C预处理组较I/R时45Ca2+摄取率降低(P<0.01)。I/R组NCXmRNA的水平比对照组显著高(P<0.01);Pra-C预处理组较I/R组NCX mRNA的水平显著低(P<0.01)。各组间PMCA的活性无显著性差异。结论Pra-C可显著减轻I/R损伤;其对I/R心肌的保护与下调细胞膜NCX mRNA的转录和其蛋白的活性有关。更多还原

【Abstract】 AIM To explore the cardioprotective mechanism of praeruptorin C(Pra-C)during ischemia/reperfusion.METHODS Cultured rat neonatal cardiomyocytes were randomly divided into 3 groups: ischemia/reperfusion group(9 h ischemia followed by 1 h reperfusion,I/R),Pra-C pretreatment group(pretreated with Pra-C for 1 h before I/R) and control group.The leakage of intracellular lactate dehydrogenase(LDH) in various groups was determined by biochemical autoanalyzer.Activity of natrium-calcium exchanger(NCX) was indicated by Na+-dependent 45Ca2+ uptake tested by liquid scintillation counting.Semi-quantitative RT-PCR was employed to detect the mRNA level of NCX.Activity of plasma membrane calcium ATPase(PMCA) was determined by microcolorimetrg of inorganic phosphorus.RESULTS Compared with that in I/R group,the LDH leakage in Pra-C pretreatment group was significantly reduced(P<0.01).The Na+-dependent 45Ca2+ uptake was significantly increased in I/R group(P<0.01) compared with that in control group.This increase could be significantly attenuated in Pra-C pretreatment group.The level of NCX mRNA in I/R group was also significantly increased(P<0.01) compared with that in control group and this increase could be significantly attenuated in Pra-C pretreatment group(P<0.01).No significant change of PMCA activity was observed between various groups.CONCLUSION NCX mediates the cardioprotective effect of Pra-C during ischemia/reperfusion in the neonatal rat cardiomyocytes I/R model.更多还原