甲基黄酮醇胺对阿霉素诱导的小鼠心肌损伤的保护作用及其机理

目的 :研究甲基黄酮醇胺 (methylflavono lamine ,MFA)对阿霉素诱导的心肌损伤的保护作用及机理。方法 :用阿霉素 (adriamycin ,ADR )1.5mg·kg-1,隔日 1次ip ,共 10d ,诱导小鼠心肌损伤。所有受试动物给药前均描记肢体导联心电图 ,心电图异常的动物剔除。观察各组动物的心电图J点抬高、QRS时间和Q -T间期延长的程度、血清磷酸肌酸激酶 (CK)、血清乳酸脱氢酶 (LDH)和心肌脂质过氧化产物丙二醛 (MDA)的含量及超氧化物歧化酶 (SOD)活性的变化。血清磷酸肌酸激酶、血清乳酸脱氢酶用比色法测定 ,超氧化物歧化酶用羟胺法测定 ,丙二醛用硫代巴比妥酸 (TBA)法测定。结果 :阿霉素可使小鼠的心电图J点异常抬高 ,QRS时间和Q T间期延长 ,小鼠血清CK、LDH含量增加 ,表明阿霉素可引起小鼠心肌细胞广泛损伤 ,阿霉素诱导小鼠心肌损伤模型成立。甲基黄酮醇胺能逆转ADR效应 ,能减轻小鼠急性心肌损伤时ECG的异常变化 ,降低血清LDH与CK含量 ,使心肌损害减轻。同时 ,阿霉素可以降低心肌组织中SOD的活性 ,增加心肌组织中MDA的含量 ,而甲基黄酮醇胺能增加心肌组织SOD活性 ,降低心肌组织中MDA含量 ,表明ADR的心脏毒性是由于诱导心脏产生自由基所致 ,而甲基黄酮醇胺则通过清除氧自由基和抗脂质过氧化作用来保护心肌细胞免受损伤     

甘草酸二铵对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响

目的:观察甘草酸二铵(DG)对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响。方法:雄性wistar大鼠30只,随机分为假手术组、缺血再灌注组和DG20mg·kg-1组。每组10只。采用在体大鼠心肌缺血30min再灌注60min损伤模型,再灌注60min后分别用比色法测定心肌丙二醛(MDA)含量、超氧化物歧化酶(SOD)、三磷酸腺苷酶(ATP酶)、血清磷酸肌酸激酶(CPK)和乳酸脱氢酶(LDH)水平,并用酶组织化学方法检测心肌组织琥珀酸脱氢酶(SDH)的活性。结果:DG能显著降低心肌组织中MDA含量和SDH的活性(P<0.05,P<0.01),提高SOD和ATP酶活性(P<0.05,P<0.01),并减少心肌CPK和LDH的释放(P<0.05,P<0.01)。结论:DG具有保护大鼠心肌缺血再灌注损伤的作用,其作用机理可能与其降低心肌脂质过氧化,增强心肌细胞SOD、SDH和ATP酶活性有关。     

白藜芦醇对小鼠阿霉素性心肌损伤的保护作用及机制

目的研究白藜芦醇(Res)对阿霉素(ADM)诱导的心肌损伤的保护作用及机制。方法一次性腹腔注射ADM(15mg·kg-1),建立小鼠阿霉素急性心肌损伤模型,并观察白藜芦醇预防性给药的保护作用。结果与正常对照组相比,ADM可使小鼠心电图QRS波电压幅度下降(P<0.01),心律失常率发生达60%;心肌超微结构损伤明显;血清中MDA、NO含量及LDH活性升高,SOD活性降低;p53蛋白表达升高(P<0.01)。与ADM损伤组相比,5、10、15mg·kg-1白藜芦醇呈剂量依赖性降低血清LDH活性和MDA、NO含量,增加SOD活性;减少QRS波电压下降幅度和心律失常发生率;下调p53蛋白表达(P<0.01或P<0.05);减轻电镜下心肌超微结构损伤。白藜芦醇对正常小鼠仅升高SOD活性,对其余指标无明显影响。结论Res对阿霉素性心脏损伤具有保护作用,其机制可能与其增强心肌SOD活力、抗脂质过氧化和抑制心肌细胞凋亡有关。     

阿霉素诱导小鼠氧化应激性心肌病模型的研究

目的 研究阿霉素不同给药方案诱导小鼠氧化应激性心肌病模型的较优方案.方法 将小鼠随机分为正常组、模型1、2、3组;分别于第1、7、13天ip给予模型1组小鼠5、5、15 mg· kg-1阿霉素,一次性大剂量ip给予模型2组小鼠25 mg·kg-1阿霉素,间隔6d,分别于尾静脉注射给予模型3组小鼠5、10 mg·kg-1阿霉素;于末次给药后48 h测定各组小鼠血浆中乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)的活性和丙二醛(MDA)的含量,及心肌组织中的谷胱甘肽(GSH)、巯基的含量和ATP酶系的活性.结果 与正常组相比,3个模型组小鼠血浆中LDH的活性和MDA的含量均明显升高,SOD的活性与心肌组织中GSH的含量均明显降低,模型1组的LDH活性显著高于其他两模型组的;模型1组的CAT、GSH-Px活性与巯基含量较正常组均明显降低,而模型2组和模型3组的与正常组的无显著性差异;模型2、3组心肌组织中ATP酶的活性较正常组的明显降低,降低作用较模型1组的强.结论 模型1的造模方法较模型2、3的方案在对心脏的损伤、体内抗氧化酶系统的影响上更严重;但模型2、3的方案对抗氧化非酶系统及心肌组织ATP酶系的影响较严重.     

槲皮素对阿霉素致小鼠心肌损伤的保护作用及其机制

观察槲皮素对阿霉素致小鼠心肌损伤的保护作用并初步探讨其机制。腹腔注射阿霉素(20 mg·kg^-1)复制小鼠心肌损伤模型，检测心电图、心肌超微结构，血清NO含量和iNOS活性，心肌组织LDH、SOD、MDA的水平和p53蛋白表达。并观察槲皮素(50，100及200 mg·kg^-1)对上述指标的影响。阿霉素可导致小鼠心律失常和心肌超微结构损伤；使NO、iNOS、MDA和LDH的水平升高，SOD的水平降低；p53蛋白表达增强。槲皮素(50，100及200 mg·kg^-1)可拮抗阿霉素所致的上述变化。槲皮素对阿霉素性小鼠心肌损伤具有保护作用，其机制与增强SOD活力、降低iNOS活性、抑制p53蛋白表达等有关。     

黄柏提取物对大鼠心肌损伤的保护作用

摘 要 目的：探讨黄柏水提物和醇提物对垂体后叶素和盐酸异丙肾上腺素致大鼠心肌损伤的保护作用及其可能的作用机制。方法: 将SD大鼠随机分为正常对照组、模型组、复方丹参片组、黄柏水提组、黄柏醇提组,建立垂体后叶素和盐酸异丙肾上腺素大鼠心肌损伤模型,检测血清中肌酸激酶（CK）、乳酸脱氢酶（LDH） 活性、心肌组织超氧化物歧化酶（SOD）活性和丙二醛（MDA）含量。 结果: 与正常对照组比较,垂体后叶素建立的大鼠心肌损伤模型组血清LDH活性、CK活性和心肌组织MDA含量明显升高,心肌组织SOD活性明显降低（P<0.01）;盐酸异丙肾上腺素建立的大鼠心肌损伤模型组心肌组织MDA含量明显升高,心肌组织SOD活性明显降低（P<0.01）。与垂体后叶素建立的大鼠心肌损伤模型组相比较,各给药组血清LDH活性、CK活性和心肌组织MDA含量明显降低,心肌组织SOD活性明显升高,差异有统计学意义（P<0.05或P<0.01）;与盐酸异丙肾上腺素建立的大鼠心肌损伤模型组相比较,各给药组心肌组织中MDA含量明显降低,SOD活性明显升高,差异有统计学意义（P<0.05或P<0.01）。结论:黄柏提取液对垂体后叶素和盐酸异丙肾上腺素引起的大鼠心肌损伤有一定保护作用。     

血栓通预处理对大鼠心肌缺血再灌注损伤的影响

目的:研究血栓通对大鼠缺血心肌的保护作用。方法:选用40只Wister大鼠分为正常对照组、模型组、血栓通组及维拉帕米组,采用结扎大鼠冠状动脉左前降支建立出大鼠心肌缺血再灌注损伤模型。检测大鼠血清磷酸肌酸激酶(CPK)、乳酸脱氢酶(LDH)、血清及心肌组织超氧化物歧化酶(SOD)和脂质过氧化物丙二醛(MDA),研究血栓通对心肌梗死范围的影响。结果:血栓通可对抗结扎大鼠冠状动脉左前降支所致的大鼠急性心肌损伤,使心肌缺血大鼠的CPK及LDH降低,并可增加心肌组织SOD的活性,减少MDA生成且能显著缩小心肌梗死的范围。结论:血栓通对大鼠心肌缺血有保护作用,其机制可能与抗脂质过氧化反应有关。     

吴茱萸次碱对实验动物急性心肌缺血损伤的保护作用

目的探讨吴茱萸次碱(Rut)对实验动物急性心肌缺血损伤的保护作用。方法采用垂体后叶素及异丙肾上腺素致小鼠急性心肌缺血模型,检测血清中乳酸脱氢酶(LDH)、肌酸激酶(CK)的活性。进一步采用大鼠冠状动脉结扎模型,检测血流动力学指标及血清LDH、CK、超氧化物歧化酶(SOD)的活性及丙二醛(MDA)的含量。结果与模型组相比,Rut组能降低垂体后叶素及异丙肾上腺素所致小鼠血清LDH及CK的升高(P<0.05)。在大鼠冠状动脉结扎实验中,与模型组相比,Rut组能改善结扎大鼠血流动力学指标的变化,血清中LDH、CK的酶活力及MDA的含量下降,SOD活力升高(P<0.05)。结论 Rut对实验动物急性心肌缺血有一定的保护作用。     

大蒜多糖对阿霉素所致小鼠心脏毒性的拮抗作用

目的　研究大蒜多糖 (GP)对中毒性心肌炎的拮抗作用并探讨其机制。方法　建立小鼠阿霉素 (ADR)中毒性心肌炎模型,测定血清、心肌多项生化指标,并观察心肌结构变化。结果　ADR(3mg·kg-1ip, qod×7)可致小鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、谷草转氨酶(GOT)和诱导型一氧化氮合酶(iNOS)活力升高(P<0 01),同时心肌超氧化物歧化酶(SOD)活力下降而丙二醛 (MDA)含量升高 (P<0 01),线粒体水肿明显。GP( 0 75 ~3 0g·kg-1 ig, qd×15)能逆转ADR所致的上述改变,表现为剂量相关性降低血清CK、LDH、GOT和iNOS活力,增加心肌SOD活力和降低MDA含量,尤其以GP大剂量组作用明显 (P<0 05或P<0 01)。光镜和电镜结果也证实了GP的保护作用。结论　GP能拮抗阿霉素所致的小鼠中毒性心肌炎,其作用机制与增强心肌SOD活力和抗心肌脂质过氧化有关。     

PNU282987对异丙肾上腺素所致小鼠心脏重塑的保护作用

目的通过建立异丙肾上腺素所致小鼠心脏重塑模型,观察PNU282987保护心脏的作用。方法连续7 d皮下注射异丙肾上腺素(ISO),诱导小鼠心脏重塑模型,同时腹腔给予PNU282987,检测小鼠心脏重量指数、血清乳酸脱氢酶(LDH)和肌酸激酶(CK)的活性,观察心肌病理形态学的改变;检测心肌组织中超氧化物歧化酶(SOD)和丙二醛(MDA)的含量,通过Western blot测定诱导型一氧化氮合酶(iNOS)的表达。结果与正常对照组相比,异丙肾上腺素组心脏重量指数增加,血清LDH和CK水平显著升高,心肌SOD活性下降,MDA含量增加,心肌组织中iNOS蛋白表达增加;与模型组比较,PNU282987可显著降低心脏重量指数、血清LDH和CK水平,增加心肌SOD活性,降低心肌MDA含量,下调iNOS表达。结论 PNU282987可能通过清除氧自由基,降低iNOS的表达,保护异丙肾上腺素导致的小鼠心脏重塑。     

芹菜素对阿霉素所致心脏毒性拮抗作用的研究

目的:研究芹菜素(API)对阿霉素所致中毒性心肌炎的拮抗作用。方法:120只健康昆明种小鼠随机分为6组:正常组、ADR模型组(27 mg·kg^-1)、芹菜素低剂量组(125 mg·kg^-1)、芹菜素中剂量组(250 mg·kg^-1)、芹菜素高剂量组(500 mg·kg^-1)、芹菜素高剂量对照组(500 mg·kg^-1)。观察各组小鼠的精神状态、进食、粪便及皮毛情况。ADR末次给药24 h后,检测小鼠全心质量指数(HW/BW),心肌组织匀浆后测定SOD活力和MDA含量变化,HE染色和透射电镜观察心肌形态学和超微结构改变。结果:ADR模型组小鼠精神状态差、体质量减轻、死亡率增加、HW/BW值降低、心肌组织SOD活力下降而MDA含量增加,与正常对照组小鼠有显著性差异(P<0.01)。光镜和电镜观察发现心肌损伤明显。芹菜素组可逆转上述表现,尤以芹菜素高剂量组作用明显,与ADR组比较有显著性差异。结论:芹菜素对阿霉素所致的小鼠心脏毒性具有拮抗作用。     

Protective effect of lycopene on adriamycin-induced cardiotoxicity and nephrotoxicity

The aim of this study was to investigate the possible protective role of lycopene on adriamycin (ADR)-induced heart and kidney toxicity using biochemical and histopathological approaches. Rats were randomly divided into four groups. The first group received no medication and was regarded as the control group; the second group was injected with a single dose of ADR; the third group was treated with lycopene for 10 days before ADR injection and the last group was treated with lycopene for 2 days before and for 3 days after the administration of a single dose of ADR. ADR (10mg/kg) was intraperitoneally (i.p.) injected as a single dose and lycopene (4 mg/kg) was administered in corn oil by gavage. The levels of malondialdehyde (MDA) and reduced glutathione (GSH) in both the heart and kidneys were higher in the group treated with ADR alone than in the control group, and were lower in the groups administered with lycopene than in the ADR alone group. Although the activity of catalase (CAT) in the heart was higher in the ADR alone group than in the control group, it was lower in the kidneys. In particular, treatment with lycopene post-injection normalized both cardiac and kidney CAT activities. In heart and kidney tissues, glutathione peroxidase (GSH-Px) activities were not significantly different between all groups. Significant increases in the levels of plasma creatinine and urea were observed in the ADR group when compared to the control group, and these increases were normalized by lycopene treatment. Cardiac and renal histopathological changes were observed in the ADR group as compared to the control group. In contrast, these histopathological changes appeared nearly normal in the groups treated with lycopene pre- and post-injection. In conclusion, this study clearly indicated that ADR treatment markedly impaired cardiac and renal function and that treatment with lycopene might prevent this toxicity in rats.     

Might adriamycinol contribute to adriamycin-induced cardiotoxicity?

The pharmacokinetics of adriamycin (ADR) and its 13-hydroxylated-metabolite adriamycinol (ADR-ol) was investigated during treatment with ADR in rats at a dose of 2 mg/kg i.v., once a week for 3 weeks. At various times, samples of blood and cardiac and pulmonary tissues were collected to measure the amount of ADR and ADR-ol by an HPLC procedure. Periodical ECG monitoring was performed during the study; the severity of cardiac lesions was histologically evaluated at the end of treatment. During the first 180 min after ADR administration, plasma levels of ADR and ADR-ol rapidly decreased; ADR levels in cardiac and in pulmonary tissues increased between the 15th and 30th min and than decreased between the 60th and 180th min; on the contrary, ADR-ol was undetectable in either cardiac or pulmonary tissues during the first 3 hours following ADR administration. Between the 1st and 3rd weeks of treatment, plasmatic levels of ADR and ADR-ol were unchanged; in a similar way, both cardiac and pulmonary tissue levels of ADR were constant during the period of treatment. By contrast, the cardiac tissue level of ADR-ol significantly increased between the 2nd and 3rd weeks. ECG tracings showed maximal enlargement of both QRS and S alpha T at the end of the 3rd week. The histological examination of cardiac tissue indicated the occurrence of degenerative changes in 20% of rats at the end of the experiment. Overall results seem to indicate that ADR-ol is produced and stored in cardiac tissue during repeated ADR administration; as a consequence the cytotoxic metabolite might contribute to the cardiotoxic effect of ADR.     

Copper status and adriamycin treatment: effects on antioxidant status in mice

The biochemical response of Cu-sufficient and Cu-deficient mice to adriamycin (ADR) treatment was evaluated. Mice were injected intraperitoneally with ADR (17 mg/kg body wt.) or saline (0.9% w/v) and killed 4 d after injection. There was no effect of ADR on cardiac superoxide dismutase (SOD) activity in Cu-sufficient of Cu-deficient mice. ADR injection resulted in higher cardiac glutathione (GSH) concentrations in Cu-sufficient mice while it resulted in lower GSH concentrations in Cu-deficient mice relative to their saline-injected controls. The effects of ADR in Cu-deficient mice were tissue-specific as its administration resulted in lower hepatic SOD activity and higher hepatic GSH concentrations relative to saline-injected controls.     

The protective effect of glutathione administration on adriamycin-induced acute cardiac toxicity in rats.

Adriamycin (ADR) is a potent antitumor antibiotic drug known to cause severe cardiac toxicity. Although ADR generates free radicals, the role of these radicals in the development of cardiac toxicity is still not well understood. In the present study, we evaluated the effect of glutathione (GSH) supplementation or depletion on ADR-induced cardiotoxicity in male Wistar rats. Cardiac toxicity was induced by a single intraperitoneal injection of ADR (20 mg kg(-1)) and manifested by an increase in heart rate, blood pressure elevation, and increased serum creatine kinase (CK) and lactate dehydrogenase (LDH). The extent of lipoprotein oxidation, lipid peroxide measured as malondialdhye (MDA), total homocysteine (tHcy), lipid profile, and atherogenic index were markedly elevated, whereas cardiac GSH content was dramatically decreased in ADR rats. Pre- and co-treatment of ADR rats with GSH (5 mm kg(-1)) (ADR +GSH) markedly reduced the levels of CK, LDH, lipoprotein oxidation susceptibility, cardiac MDA, tHcy and atherogenic index, and elevated GSH levels in cardiac tissues. In contrast, GSH depletion through administration of l-buthionine-(S,R)-sulfoximine (BSO) (15 mm kg(-1)) before and after ADR injection (ADR +BSO) greatly exacerbated ADR cardiotoxicity compared to the control and ADR groups. Finally, there were also severe cardiac histopathological changes in ADR and ADR +BSO groups, which were nearly restored by GSH treatment. These results suggest that GSH inhibits ADR cardiotoxicity and might serve as a novel combination with ADR to limit free radical-mediated organ injury.     

蜂胶对阿霉素致心肌损伤小鼠的影响

目的 探讨蜂胶对阿霉素致小鼠心肌损伤的干预作用.方法 将32只健康昆明小鼠完全随机分为4组,各8只.优选β2环糊精包合蜂胶的最佳工艺,以该蜂胶环糊精包合物为实验药物建立小鼠阿霉素心肌损伤模型,测定血清、心肌的生化指标,并观察心肌结构变化.结果 阿霉素可致小鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)活力升高[阿霉素损伤组比正常对照组分别为(4900±270)U/L比(2970±230)U/L与(1080±213)U/L比(835±79)U/L],同时心肌超氧化物化酶(SOD)活力下降[(266±15)U/L比(427±12)U/L](均P＜0.01).蜂胶各组CK、LDH活力较阿霉素损伤组明显降低,SOD活力明显升高,其中以蜂胶大剂量组作用明显.结论 蜂胶能够拈抗阿霉素引起的自由基脂质过氧化,从而保护心肌细胞.

Abstract：

Objective To establish myocardial injury in mice model through Adriamycin and to observe the preventive effects of the propolis on adriamycin induced myocardial injury in mice. Methods To establish myocardial injury in mice model through β2 cyclodextrin optimum propolis and experimental drugs of Propolis cyclodextrin and to mensurate many biochemistry targets of blood serum and cardiac muscle, observing the change of Cardiac muscle structure. Results ADR may make creatine kinase(CK), lactic dehydrogenase (LDH) of mice blood serum high and make SOD of cardiac muscle low. Propolis can reverse the ADR result of this change. The performance is to reduce the CK and LDH of blood serum and raise the SOD of cardiac muscle by dosage relevance. The effect of big group is obvious ( P＜0.01).Light microscopy also confirmed the protective effect of propolis. Conclusion Propolis can antagonize the free radical lipid peroxidation caused by ADR, protecting myocardial cells.     

硫化氢在大鼠阿霉素心肌病发病中的意义

目的探讨新型气体信号分子硫化氢(hydrogen sul-fide,H2S)对阿霉素(adriamycin,ADR)心肌病大鼠心肌细胞凋亡的影响。方法♂性Wistar大鼠66只,随机分为6组①阿霉素组(ADR组,n=12):腹腔注射ADR,每次2.5mg.kg-1,1次/周,共用药10wk;②ADR+小剂量NaHS组(n=12):ADR用药方法同ADR组,同时经腹腔注射H2S供体NaHS,2.8μmol.kg-1.d-1,连续用药10wk;③ADR+大剂量NaHS组(n=12):ADR用药方法同ADR组,同时经腹腔注射NaHS,14μmol.kg-1.d-1,连续用药10wk;④ADR+PPG组(12只):ADR用药方法同ADR组,同时经腹腔注射PPG30mg.kg-1.d-1,连续用药10wk;⑤对照组(n=9):用相同容量的生理盐水代替ADR,给药方法同ADR组;⑥NaHS组(n=9):经腹腔注射NaHS,14μmol.kg-1.d-1,连续用药10wk。于第10周检测大鼠心功能和血流动力学指标,处死大鼠,取心肌组织制作病理切片,分别于光镜及透射电镜下观察其显微以及超微结构,用TdT介导dUTP缺口末端标记法(TUNEL)方法检测心肌细胞凋亡及用免疫组化测定心肌细胞中Fas和Bcl-2蛋白的表达,同时用敏感硫电极法测定血浆及心肌组织里的H2S含量。结果阿霉素组大鼠左室内压最大上升速率(+dp/dtmax)及左室内压最大下降速率(-dp/dtmax)明显降低(P均<0.01),心肌病理结果显示阿霉素组心肌细胞变性、线粒体和肌浆网水肿、细胞内空泡增多,呈心肌病样改变;心肌细胞凋亡数明显增加,心肌细胞中的Fas蛋白表达明显增加,Bcl-2蛋白的表达明显降低(P均<0.01);同时大鼠血浆及心肌组织H2S含量均明显低于对照组(P<0.01)。经外源性补充H2S供体NaHS后,大鼠心功能较前明显改善,光镜及电镜显示ADR+小剂量NaHS组及ADR+大剂量NaHS组心肌组织病理损害程度明显较阿霉素组减轻;心肌细胞凋亡率明显降低,Fas蛋白表达明显降低,Bcl-2蛋白表达明显增加(P均<0.01)。ADR+PPG组与ADR组相比较,差异无显著性,NaHS组和对照组相比较,差异无显著性(P>0.05)。结论H2S参与大鼠阿霉素心肌病的发病过程,外源性补充H2S供体可以改善阿霉素心肌病大鼠心功能,减轻心肌损伤,减少细胞凋亡,对其发病起到调节作用。     

阿霉素对大鼠心肌损伤的实验研究

目的观察经阿霉素(ADR)作用的实验大鼠心肌组织中丙二醛(MDA)、超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、黄嘌呤氧化酶(XOD)含量的变化。方法采用36只Wistar雌性大鼠,分生理盐水(NS)组和ADR组,ADR组尾静脉缓慢注射ADR(3mg/kg),每周一次;NS对照组尾静脉及腹腔注射等剂量NS。分别用药三周和六周后处死,观察各组大鼠心肌组织中MDA、SOD、GSH及XOD含量的变化。结果 ADR组MDA与XOD含量均升高,SOD与GSH含量均下降。结论过氧化反应增强、自由基生成酶活性升高及清除酶或清除剂活性降低可能参与了ADR心脏损伤的发生。     

Intracellular distribution of peroxynitrite during doxorubicin cardiomyopathy: evidence for selective impairment of myofibrillar creatine kinase

Cardiac peroxynitrite and protein nitration are increased during doxorubicin cardiotoxicity, but the intracellular targets and functional consequences have not been defined. We investigated the intracellular distribution of protein nitration during doxorubicin cardiotoxicity in mice. Following in vivo cardiac function assessments by echocardiography, cardiac tissues were prepared for immunohistochemistry and electron microscopy 5 days after doxorubicin (20 mg kg(-1)) or vehicle control. Increased cardiac 3-nitrotyrosine was observed using light microscopy in doxorubicin treated animals. Immunogold electron microscopy (55,000x) revealed increased myofibrillar and mitochondrial 3-nitrotyrosine levels following doxorubicin, but cellular 3-nitrotyrosine density was 2 fold higher in myofibrils. We therefore investigated the actions of peroxynitrite on intact cardiac contractile apparatus. Skinned ventricular trabeculae were exposed to physiologically relevant peroxynitrite concentrations (50 or 300 nM) for 1 h, then Ca(2+) induced contractile responses were measured in the presence of ATP (4 mM) or phosphocreatine (12 mM) as high energy phosphate supplier. ATP maximal force generation was unaltered after 50 nM peroxynitrite, but phosphocreatine/ATP response was reduced (0.99+/-0.63 vs 1.59+/-0.11), suggesting selective inactivation of myofibrillar creatine kinase (MM-CK). Reduction of ATP maximal force was observed at 300 nM peroxynitrite and phosphocreatine/ATP response was further reduced (0.64+/-0.30). Western blotting showed concentration dependent nitration of MM-CK in treated trabeculae. Similarly, cardiac tissues from doxorubicin treated mice demonstrated increased nitration and inactivation of MM-CK compared to controls. These results demonstrate that peroxynitrite-related protein nitration are mechanistic events in doxorubicin cardiomyopathy and that the cardiac myofibril is an important oxidative target in this setting. Furthermore, MM-CK may be a uniquely vulnerable target to peroxynitrite in vivo.     

SD大鼠阿霉素慢性心力衰竭模型的建立与评价

目的通过尾静脉注射阿霉素建立SD大鼠慢性心力衰竭模型,并对其进行评价。方法成年♂SD大鼠随机分为两组:正常对照组(CON组,n=8)和阿霉素心力衰竭组(ADR组,n=20)。ADR组尾静脉注射阿霉素2 mg.kg-1,每周1次,计6周,累积剂量达12 mg.kg-1;CON组静脉注射等容积0.9%的氯化钠溶液,周期同前。末次注射2周后图测定心功能包括左心室舒张末内径(LVEDD)和收缩末内径(LVESD)并计算左室短轴缩短率(LVFS)及射血分数(LVEF);病理学检测包括HE及VG染色观察心肌组织形态学改变;ELISA法测定血浆BNP浓度。结果与CON组相比,ADR组大鼠LVEDD和LVESD增加,LVFS和LVEF明显下降(P<0.01);HE染色可见部分心肌纤维断裂,心肌间质炎细胞浸润;VG染色心肌间质胶原容积分数(CVF)及心肌血管周围胶原面积(PVCA)明显增加(P<0.01),心肌纤维化明显;血浆BNP水平升高(P<0.01)。结论静脉多次注射阿霉素能够导致SD大鼠心功能降低和心肌组织形态学改变,成功建立可靠的非缺血性慢性心力衰竭模型。