【作者】 王占庆；

【导师】 许景峰；

【作者基本信息】 中国人民解放军军事医学科学院 ， 药理学， 2007， 博士

【摘要】 目的：研究阿魏硝胺(FLNT)对心肌缺血／再灌注(I／R)的保护作用并探讨其可能作用机制。方法：建立大鼠在体I／R模型、后期预适应(LPC)模型，测定心肌保护的血清学和组织学指标，观察FLNT对I／R损伤的治疗作用和LPC预防性保护作用；建立血管张力体外模型观察FLNT对KCl、去甲肾上腺素和乙酰胆碱等预收缩的外周血管和冠脉血管舒张作用；运用鸟苷酸环化酶(GC)和钾通道的阻断剂预孵育血管和膀胱平滑肌，观察FLNT对GC酶和钾通道的作用；对FLNT代谢后血清和尿液样品进行HPLC-MS-MS分析，观察FLNT的主要代谢途径，并对其主要代谢物进行抗心肌I／R损伤和血管舒张的活性研究。结果：FLNT对I／R损伤有治疗性和预适应性保护作用，它显著减少梗死范围(IS)，降低血清中肌酸激酶(CK)，和乳酸脱氢酶(LDH)的水平，减轻细胞膜损伤；减轻心肌缺血／再灌造成心电图的改变；提高组织中NO的含量；降低膜脂质过氧化产物丙二醛的水平，提高机体的抗氧化能力。另外，FLNT能诱导心肌后期缺血预适应，减少IS，降低CK、LDH水平，提高I／R后心肌组织中Mn-SOD和Bcl-2／Bax的水平，增强了机体的抗氧化和抗凋亡的能力，提高无I／R过程的心肌组织中诱导型一氧化氮合成酶(iNOS)的水平，为LPC提供保护介质。FLNT对离体外周血管和冠脉血管都有剂量依赖性舒张作用，对动脉血管平滑肌的舒张为非内皮依赖的，鸟苷酸环化酶(GC)抑制剂能明显减弱FLNT的血管舒张作用。FLNT能显著减弱血管平滑肌和膀胱平滑肌内向整流性、ATP依赖性和钙离子激活性钾通道阻断剂的血管收缩作用。FLNT的代谢途径有脱硝基和脱乙酰基两种途径，其中脱乙酰基代谢物去乙酰阿魏硝胺(N-(2-羟乙基)阿魏酰胺硝酸酯，DFNT)和FLNT一样有抗心肌I／R损伤和舒张血管的活性。结论：FLNT有抗心肌缺血／再灌注损伤的治疗性和缺血预适应性保护作用；有舒张外周血管，冠脉血管和膀胱平滑肌的活性，对动脉血管平滑肌的舒张为非内皮依赖的。其作用机制可能与其作为NO供体，刺激鸟苷酸环化酶和开放钾离子通道，抑制电压依赖性钙通道或受体操纵性钙通道，降低细胞内钙释放、阻止细胞外钙内流有关而舒张血管，增强机体抗氧化和抗凋亡能力作用有关。FLNT脱乙酰基主要代谢物DFNT有抗心肌缺血／再灌注损伤和血管舒张的活性。更多还原

【Abstract】 Aim: to investigate the cardioprotection of N—2-(acetylferulamidoethyl)nitrate(FLNT) against myocardium ischemia/reperfusion(I/R) injury and the possible mechanismMethods: Three varieties of animal experimental models were successfully made: myocardium ischemia/reperfusion (I/R), late ischemia preconditioning (LPC) and vessel tension in vitro. The makers of cardioprotection against myocardium I/R damage were investigated. The vessel tension was investigated to study the vasorelaxation effect of FLNT in vitro. And the the blockers of guanylate cyclase(GC) and potassium channels were used to study the possible mechanism of vasoreactivity. The serum and urine were analysed through HPLC-MS-MS to identify the possible metabolites of FLNT in rats. And the activity of the major metabolite DFNT on the cardioprotection against myocardium I/R injury and its vasoactiviry was also investigated.Results: FLNT could protect rats myocardium against I/R through the stragies of treatment and preconditioning. It diminished the infarct size, reduced the level of creatine kinase(CK) and lactate dehydrogenase (LDH). FLNT increase the level of NO in heart tissue, reduced the level of maleic dialdehyde (MDA). FLNT also could induce late ischemia preconditioning in rats, it diminished myocardium infarct size, reduced the level of CK and LDH, increased the level of Mn-SOD and Bcl-2/Bax in heart tissue after I/R procedure, which strengthen the potency of anti-oxidant and anti-apoptosisasis, It increase the level of induced nitric oxide synthase in heart tissues without I/R procedure, which supples the effect media of LPC.FLNT could relax the peripheril vessels and coronary artery. The relaxation on arteries was endothium-independent. The blocker of guanylate cyclase(GC) could diminish the relaxation of FLNT.The metabolites of FLNT included two varaties: nitro group free metabolites and acetyl group free metabolites. The major acetyl group free metabolite (N-2-(ferulamidoethyl)nitrate(DFNT) had the activity of cardioprotection against I/R and vasorelaxation.Conclusion: FLNT had the activities of protecting myocardium against I/R injury through pathways of treatment and ischemia proconditioning. The machanis was possibly related to its characteristics of anti-oxidant, anti-apoptosis. It could relax peripheral artery and coronary artery possibly by stimulating GC and opening potassium channels as nitric oxide donor. Its major acetyl group free metabolite DFNT had the activities of cardioprotection against myocardium I/R injury and vasorelaxation.更多还原