硫化氢对截肢创伤后心肌线粒体功能的保护作用

目的 探讨外源性H2S对截肢创伤应激后心肌线粒体功能的影响，以及截肢创伤应激后，心肌线粒体损伤与H2S对心肌线粒体功能的保护作用。方法 建立截肢创伤应激模型。雄性SD大鼠48只（平均体质量260～300 g），分为正常对照组、创伤组（截肢后6 h）、NaHS组（截肢后立即腹腔注射NaHS 28 μmol/kg，6 h后处死）和炔丙基甘氨酸（PPG）组（截肢后立即给予腹腔注射PPG 50 mg/kg，6 h后处死），每组8只。提取心肌线粒体，用strathkelvin氧电极法测定线粒体的呼吸功能。用罗丹明123(Rh123)荧光测定线粒体的膜电位，用微量ATP酶试剂盒检测线粒体总ATP的变化。结果 与正常对照组比，创伤后心肌线粒体的呼吸功能受损［呼吸控制率(RCR)及磷氧比(P/O)降低，P<0.05］，膜电位下降（P<0.05），总ATP酶的含量降低（P<0.05）。与创伤组比，NaHS组心肌线粒体的呼吸功能改善（RCR、P/O升高，P<0.05），膜电位升高（P<0.05），总ATP酶的含量增加（P<0.05）。PPG组心肌线粒体的呼吸功能进一步受损（RCR、P/O降低，P<0.05），总ATP酶的含量减少（P<0.05）。结论 截肢创伤应激可使心肌线粒体的呼吸功能受损，膜电位下降，能量代谢障碍，硫化氢对截肢创伤后心肌线粒体的损伤具有保护作用。     

藏红花素对急性心肌梗死大鼠心肌线粒体的保护作用

目的探讨藏红花素(Crocin)对急性心肌梗死(AMI)大鼠缺血区心肌线粒体损伤的保护作用及其相关机制。方法将150只SD大鼠按随机数字表法分为假手术组、AMI组和藏红花素7.5、15、30 mg/kg组,各30只;通过结扎左冠状动脉前降支复制AMI大鼠模型,藏红花素各组于造模手术前10 min腹腔注射给药,假手术组和AMI组给予生理盐水。24 h后,通过透射电子显微镜观察缺血区心肌线粒体超微结构变化,通过荧光分光光度计检测膜电位、膜通透性转换孔(MPTP)开放度;氧电极法检测呼吸功能指标[态3呼吸(R3)、态4呼吸(R4)、呼吸控制率(RCR)],比色法检测呼吸酶活性、ATP含量,定磷法检测心肌Na~+-K~+-ATP酶、Ca~(2+)-ATP酶活性,原子化学发光法测定线粒体Ca~(2+)浓度。结果与AMI组比较,藏红花素15、30 mg/kg组线粒体肿胀、膜破裂、嵴断裂溶解等超微结构病变明显改善,膜电位升高且MPTP开放度降低(P0.01),R3、RCR升高且R4降低(P0.05或P0.01),线粒体呼吸酶(NADH脱氢酶、琥珀酸脱氢酶、细胞色素C氧化酶)活性、ATP含量且心肌Na~+-K~+-ATP酶、Ca~(2+)-ATP酶活性升高(P0.05或P0.01),线粒体Ca~(2+)浓度降低(P0.05或P0.01)。结论藏红花素对AMI大鼠缺血区心肌线粒体结构和功能具有保护作用,作用机制可能与抑制线粒体Ca~(2+)浓度升高有关。     

冬虫夏草提取液对肝线粒体氧化磷酸化功能的影响

目的探讨冬虫夏草提取液(CSE)对糖尿病(DM)小鼠肝线粒体氧化磷酸化功能的影响。方法用四氧嘧啶(Alloxian)建立DM小鼠模型,将DM模型小鼠随机分为模型组和CSE保护组,另设正常对照组及维生素E保护组。利用极谱法在线粒体水平测定以琥珀酸(S)为底物的呼吸控制:态3呼吸速率(R3)、态4呼吸速率(R4)、呼吸控制比(RCR)和磷/氧比(P/O);采用化学发光法测定O2的生成量;通过荧光素-荧光素酶的方法测定H+-ATP酶合成活力;比色法测定抗氧化酶的活性。结果模型组小鼠线粒体呼吸链RCR、P/O、ATP合酶活性以及抗氧化酶活性与正常对照组比较显著降低(P0.001),态4、O2与正常对照组比较显著增高(P0.01);CSE保护组呼吸链RCR、P/O、ATP合酶活性以及抗氧化酶活性显著高于DM组,态4、O2含量显著低于DM组(P0.01),保护作用优于维生素E组。结论 CSE对DM肝线粒体的氧化应激有保护作用。     

左卡尼汀强化St.Thomas No.2液对长时间冷保存离体心脏能量代谢的影响

目的 探讨不同剂量的左卡尼汀（LCN）添加至St.Thomas No.2液后对长时间冷保存离体大鼠心脏能量代谢的影响.方法 利用Langendorff灌注装置建立离体大鼠心脏模型.SD大鼠56只随机分为4组：对照组8只、St组16只（该组使用St.Thomas No.2液为心脏停搏液和保存液）、LCN 1组16只（St.Thomas No.2液加LCN 12g/L为心脏停搏液和保存液）和LCN 2组16只（St.Thomas No.2液加LCN 6g/L为心脏停搏液和保存液）.对照组直接取左心室心肌组织,其他各组16只大鼠中8只在4℃条件下保存心脏7h后取左心室心肌,另外8只建立离体左心工作模型,再灌注30min后取左心室心肌.检测心肌三磷酸腺苷（ATP）、二磷酸腺苷（ADP）、一磷酸腺苷（AMP）、总腺苷（TNA）含量并计算能荷（EC）;提取心肌线粒体后检测线粒体内Ca^2＋含量（[Ca^2＋]m）及线粒体呼吸功能.结果 St组冷保存后心肌ATP含量和EC显著下降,[Ca^2＋]m显著增高,线粒体呼吸控制率（RCR）明显降低（P〈0.05）;再灌注后心肌ATP含量及EC无明显改善,[Ca^2＋]m进一步增高,RCR进一步降低（P〈0.05）.LCN 1组及LCN 2组各项指标较St组显著改善（P〈0.05）,两治疗组之间比较差异亦有统计学意义.结论 不同剂量的左卡尼汀添加至St.Thomas No.2液可减轻线粒体钙超载,改善心肌能量代谢,对心肌细胞线粒体有较好的保护作用.此保护作用与LCN剂量有关.     

重组人纽兰格林对心力衰竭大鼠线粒体功能的影响

目的观察重组人纽兰格林(neuregulin,NRG)对心力衰竭(HF)大鼠线粒体功能的影响,并探讨其机制。方法雄性Wister大鼠40只,结扎大鼠左冠状动脉建立缺血性HF模型。4周后,建模成功的24只大鼠随机分为NRG组[NRG 10μg/(kg·d)],AG825组[AG825 50μg/(kg·d)]及HF组,各组8只,另6只大鼠作为假手术组(Sham组)。各组干预10 d,于实验结束时提取左心室梗死区外心肌线粒体,测定线粒体膜电位(MMP)、呼吸控制率(RCR)及组织ATP酶活性,同时测定活性氧水平及谷胱甘肽过氧化物酶(GSHPX)mRNA水平。结果与Sham组比较,HF组大鼠线粒体功能受损,MMP下降、RCR及ATP酶活性降低,活性氧生成增加,GSHPX mRNA表达减少。与HF组比较,NRG组大鼠MMP增高,线粒体RCR改善,ATP酶活性增多,活性氧生成减少,GSHPXmRNA表达增加,而AG825组RCR、MMP和ATP酶活性均明显降低(P<0.05,P<0.01)。结论 NRG明显改善衰竭大鼠线粒体功能,NRG对衰竭心肌线粒体功能的保护作用,可能与其抗氧化应激作用有关。     

补肾复方抗老年大鼠肝肾线粒体老化的实验研究

目的　观察补肾复方抗老年大鼠肝肾线粒体老化的作用 ,为“肝肾同源”提供实验依据。方法　实验大鼠分青年和老年组 ,其中老年组分空白对照组和补肾复方治疗组。采用荧光光度计测定肝肾线粒体内膜流动性 ,比色测磷法测定肝肾线粒体内膜 ATP酶活力 ,生物组织测氧仪测定肝肾线粒体氧化磷酸化效率 (ADP/ O)及呼吸控制率 (RCR) ,透射电镜观察肝肾线粒体形态及形态计量学分析。结果　老年大鼠肝肾线粒体内膜流动性、ATP酶活力、ADP/ O和 RCR均较青年组明显降低 ,而服用补肾复方 2个月后的老年大鼠上述指标均明显增高 (P<0 .0 5或 P<0 .0 1 ) ;透射电镜形态及形态计量学分析结果表明 ,老年组肝肾线粒体肿胀变性 ,补肾复方治疗后 ,肝肾线粒体超微结构变化得到明显改善 (P<0 .0 5或 P<0 .0 1 )。结论　补肾复方对老年大鼠肝肾线粒体老化的结构和功能均有一定的防护 ,线粒体可能是“肝肾同源”的重要物质基础之一。     

螺内酯通过上调沉默信息调节因子1减轻异丙肾上腺素诱导大鼠心肌纤维化

目的探讨螺内酯减轻大鼠心肌纤维化是否与沉默信息调节因子1(SIRT1)的表达变化有关。方法雄性SD大鼠40只,随机均分为对照组、模型组、低剂量螺内酯组、高剂量螺内酯组。后3组皮下注射异丙肾上腺素[5 mg/(kg·d),连续7天]建立大鼠心肌纤维化模型,低剂量螺内酯组、高剂量螺内酯组大鼠在给予异丙肾上腺素的同时分别给予30、60 mg/(kg·d)螺内酯灌胃,对照组给予相同体积的生理盐水,共21天。Powerlab生理记录仪检测左心功能变化,HE染色和Masson染色检测心肌病理改变,Western blot和实时荧光定量PCR检测大鼠心肌组织SIRT1的表达变化。结果模型组大鼠的左心室质量指数(LVWI)、右心室质量指数和左心室舒张末期压(LVEDP)显著高于对照组(P0.05);模型组左心室收缩压(LVSP)、左心室压力上升的最大变化速率(+dp/dt_(max))和左心室压力下降的最大变化速率(-dp/dt_(max))显著低于对照组(P0.05);与对照组比较,模型组大鼠心肌排列紊乱,胶原纤维增生明显,SIRT1的mRNA及蛋白表达下调(P0.05)。给予螺内酯后,大鼠的LVWI和LVEDP明显低于模型组(P0.05),LVSP、+d P/dt_(max)和-dp/dt_(max)明显高于模型组(P0.05);与模型组相比,螺内酯组大鼠心肌排列紊乱程度减弱,胶原含量减少,SIRT1的mRNA及蛋白表达上调(P0.05)。结论螺内酯减轻异丙肾上腺素诱导大鼠的心肌纤维化,其抗纤维化作用可能与上调SIRT1表达有关。     

心肌缺血膜损伤的实验研究

本实验以异丙肾上腺素性心肌缺血为模型,对心肌膜脂、膜酶和自由基系统进行了研究。实验采用SD大鼠,皮下注射异丙肾上腺素85mg/kg,24小时后将动物处死。与正常对照组比较,心肌游离脂肪酸明显增加(P<0.05),线粒体胆固醇/磷脂比值和膜脂流动性升高(P值分别小于0.05和0.001);心肌脂质过氧化产物丙二醛含量增加(P<0.05).且心肌及线粒体的超氯化物歧化酶和谷胱甘肽过氯化物酶活力均升高(P值分别小于0.01和0.05);心肌线粒体Ca~(2+)—Mg~(2+)—ATP酶活力增加,Na~+—K~+—ATP酶活力降低。但5′-核苷酸酶无明显变化。结果提示:ISP—MI大鼠心肌膜脂、膜酶及自由基代谢发生紊乱,提示心肌缺血时膜受损。     

HIF-1α在七氟醚后处理减轻大鼠心肌缺血再灌注致线粒体功能损伤中的作用研究

目的探讨缺氧诱导因子-1α(HIF-1α)在七氟醚后处理减轻大鼠心肌缺血再灌注致线粒体功能损伤中的作用。方法取Langendorff离体灌注模型成功的大鼠心脏88例,采用随机数字表法分为4组(n=22):对照组(C组)、缺血再灌注组(I/R组)、七氟醚后处理组(Spost组)和HIF-1α抑制剂2ME2组(2ME2组)。Western blot测定HIF-1α表达水平;电镜观察线粒体超微结构;汉莎氧电极法测定线粒体3态呼吸(State3)、呼吸控制比(RCR);ATP试剂盒检测ATP含量;线粒体膜电位检测试剂盒检测膜电位变化。结果与I/R组比较,Spost组HIF-1α表达上调,State3、RCR、ATP、膜电位升高(P0.05)。结论 HIF-1α表达上调改善线粒体功能是介导七氟醚后处理减轻大鼠心肌缺血再灌注损伤的重要调控机制。     

海人酸癫痫大鼠海马区能量代谢异常和线粒体功能障碍的变化

目的 观察海人酸(KA)颞叶癫痫(TLE)大鼠海马区能量代谢异常和线粒体功能障碍的变化.方法 40只大鼠随机分为对照组和模型组(6h、1、3、7d),模型组一侧海马注射KA制备癫痫大鼠模型,对照组注射相同体积生理盐水.检测各组海马三磷酸腺苷(ATP)、二磷酸腺苷(ADP)、ATP/ADP比值及线粒体酶活性.结果 KA注射后随时间延长海马区ATP含量呈明显下降的趋势(P＜0.05),且各时间点ATP表达水平均明显低于对照组(P＜0.05);而海马区ADP表达水平及ATP/ADP比值随KA注射后时间的延长呈显著升高的趋势(P＜0.05),且各时间点ADP表达水平及ATP/ADP比值均明显低于对照组(P＜0.05);KA注射后随时间延长海马线粒体呼吸链复合物Ⅱ琥珀酸脱氢酶(SDH)、复合物Ⅳ(CytoOx)和Na+-K+-ATP酶的生物学活性呈明显下降的趋势(P＜0.05),且各时间点线粒体SDH、Cyto-Ox和Na+-K+-ATP酶的生物学活性均明显低于对照组(P＜0.05).结论 KALE大鼠海马区存在明显的能量代谢异常和线粒体功能障碍情况.     

川芎嗪联合左旋精氨酸对缺血—再灌注损伤兔心肌线粒体功能的影响

目的探讨川芎嗪联用左旋精氨酸对心肌缺血-再灌注损伤时心肌细胞线粒体功能的影响。方法选用日本大耳白兔50只,随机分为正常对照组(A组)、心肌缺血-再灌注组(B组)、心肌缺血—再灌注 川芎嗪治疗组(C组)、心肌缺血—再灌注 左旋精氨酸治疗组(D组)和心肌缺血—再灌注 川芎嗪 左旋精氨酸治疗组(E组)。观察心肌线粒体呼吸功能、Ca2 浓度、丙二醛浓度、超氧化物歧化酶活性和心肌组织三磷酸腺苷(ATP)和能荷的变化。结果与A组比较,B组线粒体呼吸控制率、Ⅲ态呼吸速率和超氧化物歧化酶明显降低,Ⅳ态呼吸速率、Ca2 浓度和丙二醛显著升高,心肌组织ATP和能荷明显降低。与B组比较,C组、D组和E组线粒体呼吸控制率、Ⅲ态呼吸速率和超氧化物歧化酶明显升高,Ⅳ态呼吸速率、Ca2 浓度、丙二醛显著降低,心肌组织ATP和能荷明显增高;且与A组比较,E组上述指标均无明显差异。结论川芎嗪联用左旋精氨酸可通过降低氧自由基水平和减轻钙超载,而改善缺血—再灌注损伤心肌的线粒体功能。     

急性心肌梗死后螺内酯干预对左室重构的影响

目的　探讨急性心肌梗死(AMI)患者应用螺内酯干预对于左室重构(LVRM)的影响。方法　4家医院共入选AMI患者88例,采用多中心、随机、对照的方法,对46例AMI患者在常规治疗的基础上加用螺内酯40mg/d(螺内酯组),对照组(n=42)常规治疗。在6个月干预期内检测两组血清Ⅲ型前胶原氨基端肽(PⅢNP)、脑钠肽(BNP)及超声心动图,以评价左室纤维化、左室功能和左室容积。结果　88例中,急性前壁心肌梗死患者43例,螺内酯组23例、对照组20例;急性下壁心肌梗死患者45例,螺内酯组23例、对照组22例。急性前壁心肌梗死组在治疗3、6个月时螺内酯组与对照组相比,血清PⅢNP和BNP明显降低[PⅢNP分别为( 260 .2±59. 9 )ng/L比( 328 .0±70 .3 )ng/L, P=0 .001, ( 197 .1±46 .3 )ng/L比( 266. 7±52 .4 )ng/L, P<0. 001 ,BNP分别为( 347 .4±84 .0)ng/L比(430 .1±62 .9)ng/L, P<0 .001, (243 .7±79. 7)ng/L比(334. 6±62. 8)ng/L, P<0. 001]。治疗6个月时螺内酯组较对照组左室舒张末期内径、左室收缩末期内径明显降低[分别为(51. 0±5 .5)mm比(55. 6±4 .5)mm, P=0 .005, (35 .7±4 .6)mm比(39 .1±5 .6)mm, P=0 .046]。急性下壁心肌梗死组在治疗6个月时螺内酯组与对照组相比血清PⅢNP、BNP水平无统计学意义,(P>0 05),并且左     

病毒性心肌炎小鼠心肌线粒体结构和功能变化

目的:探讨病毒性心肌炎(VMC)小鼠心肌线粒体结构和功能变化。方法:雄性Balb/c小鼠随机分为柯萨奇B3病毒(CVB3)感染组和对照组。分别采用电镜和形态计量学方法观察心肌线粒体形态、数量和膜磷脂定位,酶细胞化学法分析线粒体细胞色素氧化酶(CCO)和琥珀酸脱氢酶(SDH)活性,反相高效液相色谱法测定心肌组织腺苷酸(ATP、ADP和AMP)含量。结果:CVB2感染组小鼠心肌线粒体大量破坏,膜磷脂严重缺失、定位改变,CCO和SDH活性降低,腺苷酸(ATP、ADP和AMP)含量下降。结论:VMC心肌线粒体结构严重破坏、功能明显下降,心肌细胞存在产能障碍。     

Effects of endurance training and acute doxorubicin treatment on rat heart mitochondrial alterations induced by in vitro anoxia-reoxygenation

Endurance training (ET) and adriamycin (ADR) treatment are two conditions that have been described as triggering metabolic alterations within the myocardium. ADR is an anti-neoplastic agent with notorious cardiotoxicity, most likely because it increases oxidative stress. ET and/or ADR treatment can induce metabolic and signaling alterations affording cross-tolerance against several insults such as ischemia and reperfusion. The objective of the present work was to investigate whether heart mitochondria isolated from rats submitted to ET with or without ADR treatment were more or less susceptible to in vitro anoxia-reoxygenation (AR) when compared with control rats. Twenty-four male Wistar rats were assigned into four groups (n=6 each): control (C), ADR (20 mg-kg⁻¹), 14 wk ET (T), and T+ADR. Respiratory parameters and oxidative damage were determined before and after 1 min anoxia followed by 4 min reoxygenation. Basal heat shock proteins (HSPs)60 and-70 and antioxidant enzymes' activity were measured. ADR by itself decreased state 3 and respiratory control ratio (RCR), as opposed to ET by itself, which improved state 3 and RCR. As expected, AR impaired state 3 and 4, RCR, and ADP/O in the C group (p>0.05). In the ADR group, AR did not induce any alteration in RCR and in ADP/O values. ET in the absence of ADR treatment prevented the impairment in RCR and ADP/O and in state 4 induced by AR. Also, despite the fact that state 3 respiration after AR was lower in all groups, it was significantly higher in the T than in the C group. Increased mitochondrial carbonyls and malondialdehyde (MDA) after AR were only found in the C group. Also, following AR, both carbonyls and MDA levels were lower in the T and in the T+ADR than in C and ADR groups, respectively. HSP60 levels were higher in the ADR, T, and T+ADR than in the C group (2.5-fold, 2-fold, and 1.9-fold increase, respectively). HSP70 increased twofold in the T and T+ADR groups. ET augmented 1.5-fold the activity of superoxide dismutase. The present work demonstrates that both ET and ADR treatment induced myocardial alterations that interfere with in vitro mitochondrial responses to AR.     

Effect of captopril on myocardial energy metabolism in chronic pressure overload rats

Objective To investigate the effects of captopril on cardiac function and levels of energy-rich phosphates in pressure overload induced left ventricular hypertrophy rats. Methods One hundred and twenty SD rats were randomly divided into three groups： sham operation group （SH group, n=40）,coarctation of abdominal aorta group （CAA group, n=40） and captopril treatment lmg~ 100g1 ~ d-1） group （CAP group, n=40）. Left ventricular end-diastolic pressure （LVEDP）, left venh-icular mass index （LVMI）, levels of energy-rich phosphates and morphological changes of the myocardial mitochondria were compared at the 62 and 82 week after operation. Results At 62 week, in CAA group, LVMI and LVEDP were increased and _ dp/dtmax was decreased, while ATP and ADP were decreased and AMP was increased （P〈0.01）. These changes were much obvious at 8th week （P〈0.01）. Compared with those of CAA group, the parameters of heart function and energy-rich phosphates （ATP, ADP, AMP, TAN） in CAP group were improved significantly（P〈0.01） at the 6th and 8th week. In CAP group, the parameters of heart function and energy-rich phosphates （ADP, AMP, TAN） were much better at 8~ week than those at 6th week. The morphological change of mitochondria was less in CAP group than that in CAA group. Conclusion Captopril significantly improves myocardial energy metabolism in pressure overload rats and protects the function of myocardial mitochondria     

Endurance training limits the functional alterations of rat heart mitochondria submitted to in vitro anoxia-reoxygenation

BACKGROUND: Studies analysing the effect of endurance training on heart mitochondrial function submitted to in vitro anoxia-reoxygenation (A-R) are missing. The present study aimed to investigate the effect of moderate endurance treadmill training (14 weeks) against rat heart mitochondrial dysfunction induced by in vitro A-R. METHODS: Respiratory parameters (state 3, state 4, ADP/O and respiratory control ratio-RCR) and oxidative damage markers (carbonyl groups and malondialdehyde) were determined in isolated mitochondria before and after 1 min anoxia followed by 4 min reoxygenation. Levels of heat shock protein 60 kDa (HSP60) and 70 kDa (HSP70) were measured before A-R in mitochondria and whole muscle homogenate, respectively. RESULTS: A-R significantly impaired the rate of state 3 and state 4 respiration, as well as the RCR and ADP/O in the sedentary group. However, mitochondrial state 3 respiration was significantly higher in trained than in the sedentary group both before and after A-R. The impairments in RCR, ADP/O ratio and state 4 induced by A-R in sedentary group were significantly attenuated in endurance-trained group. The inhibition of state 4 induced by GDP was significantly higher in trained than in sedentary group. Oxidative modifications of mitochondrial proteins and phospholipids were found in sedentary group after A-R, although limited in trained group. Increased levels of mitochondrial HSP60 and tissue HSP70 accompanied the lower decrease in the respiratory function after A-R observed in trained group. CONCLUSION: We therefore concluded that endurance training limited the impairments on rat heart mitochondria caused by the oxidant insult inflicted by in vitro A-R.