丹酚酸B对大鼠缺血心肌组织溶酶体功能的影响

目的探讨丹酚酸B(Sal B)对异丙肾上腺素(ISO)所致大鼠心肌缺血模型心肌溶酶体功能的影响。方法 SD大鼠随机分为空白组,模型组,丹参注射液组和Sal B 12.8、6.4、3.2 mg/kg组。除空白组外,各组大鼠尾静脉注射ISO建立急性心肌缺血模型,连续给药7 d后,PowerLab数据采集分析系统测定各组大鼠心电图变化;试剂盒测定血清中溶酶体相关膜蛋白2(Lamp-2)、组织蛋白酶D(Cat-D)的活性,心脏匀浆中一氧化氮合酶(NOS)、一氧化氮(NO)、Cat-D和溶酶体匀浆中Cat-D的活性;HE染色法检测心肌梗死面积。结果与空白对照组比较(P0.05或P0.01),模型组大鼠心电图T波水平显著升高,血清中Lamp-2、Cat-D的水平显著升高,心脏匀浆中NOS、NO、Cat-D含量升高,溶酶体匀浆中Cat-D含量降低,心肌梗死面积明显增多。Sal B 12.8、6.4 mg/kg组和丹参注射液组能够显著降低心电图T波升高值,降低血清lamp2、Cat-D和心脏匀浆中NOS、NO、Cat-D含量,升高心脏溶酶体匀浆Cat-D含量,与模型组比较(P0.05或P0.01)。结论 Sal B对心肌缺血的保护作用与溶酶体的膜稳定性及水解酶的活性功能有一定的关系。     

大骨节病区低硒粮饲料对大鼠心,肝组织蛋白酶D活性的影响

用大骨节病区低硒粮和加硒粮喂养大鼠60天,观察到低硒组大鼠心、肝溶酶体组织蛋白酶D活性高于加硒组,该酶活性与血硒含量呈非常显著的负相关关系,提示酶活性的增高可能与低硒导致溶酶体膜稳定性遭到破坏有关。     

溶酶体组织蛋白酶与自噬在心肌重构中的作用研究

越来越多的证据表明,心肌细胞自噬失调与心肌肥厚进展有关,然而自噬在心肌重构中的作用仍然是一个有争议的问题[14].自噬过程由多种蛋白质控制,它由自噬体的形成启动,自噬体是一种双膜囊泡,与晚期内体和溶酶体融合,促进蛋白的降解.在溶酶体蛋白中,组织蛋白酶(cathepsins,Cts)是激活自噬所需最丰富的蛋白酶[5].自...     

硒对大鼠心肌儿茶酚胺代谢的影响

本文采用高压液相色谱—电化学检测法,观察饲克山病病区低硒粮(低硒组)和病区补硒粮(补硒组)大鼠结扎冠状动脉后,心肌去甲肾上腺素和肾上腺素的变化。结果表明(?)1、两组动物结扎冠状动脉1h 后,缺血区心肌去甲肾上腺素和肾上腺素都明显低于非缺血区。2、低硒组非缺血区心肌去甲肾上腺素和肾上腺素显著高于补硒组。3、结扎冠脉后低硒组缺血区与非缺血区心肌去甲肾上腺素含量的差值明显大于补硒组。     

锰对大鼠心肌线粒体膜流动性的影响

低硒可以导致心肌线粒体膜流动性降低,呼吸酶障碍。鉴于外源性锰对大鼠体内硒的拮抗作用,本文探讨了高锰对大鼠心肌线粒体膜流动性的影响。经腹腔给大鼠注射40mg/kg氯化锰五周,致使大鼠心肌锰含量增高,而硒含量降低,全血谷胱甘肽过氧化物酶活性呈进行性下降。锰组大鼠心肌线粒体荧光偏振度及微粘度明显高于对照组大鼠。结果表明,高锰可以使大鼠心肌线粒体膜流动性明显降低。     

硒和蛋氨酸缺乏对大鼠心肌琥珀酸脱氢酶活性的影响

本文介绍了硒和蛋氨酸缺乏对大鼠心肌琥珀酸脱氢酶（ＳＤＨ）活性的影响。实验结果表明，单纯低硒或低蛋氨酸合成饲料均能引起大鼠心肌ＳＤＨ活性明显下降，而低硒低蛋氨酸的复合作用则可导致该酶活性的更进一步降低。本文尚结合克山病病因进行了探讨。     

大骨节病患者软骨中组织蛋白酶D的活性

本文测定了大骨节病和非骨关节病患者的关节软骨溶酶体组织蛋白酶 D 活性。结果表明 大骨节病患者组织蛋白酶 D 活性不论是游离型或是酶的总活性均较非骨关节病惠者的酶活性升高,游离型与酶总活性的比值也增大。     

低硒对大鼠心脏功能及心肌线粒体超微结构的影响

目的 动态观察低硒对大鼠在体心功能及线粒体超微结构的影响,探讨低硒致心肌损伤的机制.方法 断乳2周清洁级SD大鼠48只,按体质量随机分为低硒(LS)组和对照(NC)组,每组24只,雌雄各半.对照组给予常规饲料(硒含量0.10～ 0.30 mg/kg)喂养,低硒组给予人工合成低硒饲料(硒含量0.01 mg/kg)喂养.两组大鼠分别在喂养10、20、30、40周后,各选取6只,雌雄各半,2,3-二氨基奈荧光法检测血硒水平;颈动脉插管检测大鼠在体心功能;电子天平称心脏重量;透射电镜下观察心肌线粒体的超微结构并用体视学方法对线粒体结构的变化情况进行定量分析.结果 与NC组比较[(0.421±0.076)、(0.409±0.057)、(0.416±0.033)、(0.386±0.050)mg/L],LS组大鼠喂养10、20、30、40周后血硒降低[(0.102±0.018)、(0.053±0.012)、(0.045±0.014)、(0.027±0.008) mg/L,P均＜0.05].大鼠喂养到20、30、40周时,LS组左心室峰值收缩压(LVSP)[(113.30±2.21)、(103.82±5.24)、(97.74±2.87)mm Hg,1 mm Hg=0.133 kPa]和左心室内压最大上升速率(+dp/dtmax)[(7366.10±455.61)、(6160.68±402.17)、(5381.21±646.72)mm Hg· s-1]均明显低于相应NC组[(130.30±3.72)、(118.97±5.31)、(120.08±3.29)mm Hg,(10 430.00±808.56)、(8582.62±621.14)、(8295.88±1318.29)mm Hg·s-1,P均＜0.05],且LVSP和+dp/dtmax均随低硒喂养时间延长而逐渐减低(P均＜ 0.05).大鼠喂养到20、30、40周时,LS组心脏与体质量之比(HW/BW×100,0.2859±0.0081、0.2948±0.0171、0.2949±0.0056)、左心室与体质量之比(LVW/BW×100,0.2302±0.0041、0.2387±0.0131、0.2386±0.0024)、左心室与心脏重量之比(LVW/HW,0.8063±0.0122、0.8104±0.0031、0.8098±0.0109)均高于NC组(0.2798±0.0103、0.2761±0.0128、0.2718±0.0051,0.2185±0.0094、0.2145±0.0131、0.2123±0.0027,0.7813±0.0210、0.7751±0.0165、0.7815±0.0100,P均＜0.05).电镜观察可见LS组大鼠心肌线粒体嵴膜减少,线粒体明显肿胀;体视学检测大鼠在喂养到10、20、30、40周时,LS组体密度(Vv)[(0.3108±0.0053)％、(0.3286±0.0036)％、(0.3877±0.0211)％、(0.3990±0.0115)％]和面密度(Sv)[(0.0284±0.0002)、(0.0295±0.0007)、(0.0338±0.0026)、(0.0332±0.0004) μm-1]高于NC组[(0.2402±0.0143)％、(0.2375±0.0241)％、(0.2657±0.0239)％、(0.2892±0.0302)％,(0.0231±0.0015)、(0.0221±0.0019)、(0.0241±0.0014)、(0.0273±0.0028)μm-1,P均＜ 0.05];在20、30、40周时,LS组比表面积(Rsv)[(0.0899±0.0015)、(0.0868±0.0031)、(0.0835±0.0013)μm-1]低于NC组[(0.0939±0.0020)、(0.0915±0.0023)、(0.0946±0.0021)μm-1,P均＜0.05].相关性分析显示,Rsv分别与LVSP和+dp/dtmax相关(r值分别为0.508、0.502,P均＜0.01).结论 低硒可导致大鼠心肌线粒体超微结构异常,并导致心脏功能发生变化,以收缩功能损伤更为明显;线粒体的损伤与心功能减退具有相关性;线粒体在低硒致心功能受损过程中发挥重要作用.     

富含硒玉米对低硒大鼠血硒和GSH-Px活性的影响

为了研究富含硒玉米对低硒粮饲料喂养大鼠血硒状态的影响 ,观察了补充富含硒玉米或亚硒酸钠时和停止补硒后大鼠血硒水平和谷胱甘肽过氧化物酶 ( GSH- Px)活性的变化。结果显示 :1两种补硒形式均可有效地增高血浆、红细胞的硒水平和红细胞的 GSH- Px活性 ;2富含硒玉米增高和维持血浆和红细胞硒水平作用与亚硒酸钠相同 ;3富含硒玉米升高红细胞 GSH- Px活性的作用低于亚硒酸钠 ,但停止补硒后两者维持 GSH- Px活性作用相似。表明富含硒玉米能有效地改善低硒大鼠的血硒状态     

Normal lysosomal enzyme levels in hypertrophied and failing dog hearts

The activity levels of three lysosomal acid hydrolases, acid phosphatase, acid ribonuclease, and cathepsin, were determined in whole homogenates of right and left ventricular myocardium from normal and chronically stressed dog hearts. Stressed hearts were from four dogs with right ventricular hypertrophy and congestive failure induced by progressive constriction of the main pulmonary artery and from four dogs with acquired right ventricular hypertrophy secondary to pulmonary hypertension resulting from infestation with heartworms (Dirofilaria immitis). Control hearts were from four unoperated and four sham operated normal dogs. No significant differences were found that could be related to myocardial stress.     

Lysosomal enzymes in the development and regression of myocardial hypertrophy induced by systemic hypertension.

Left ventricular hypertrophy was induced in unilaterally-nephrectomized rats by excess dietary salt intake, with or without injections of deoxycorticosterone (DOCA). No changes occurred in the cardiac activities or distribution of several lysosomal enzymes (cathepsin D, acid phosphatase, β-acetylglucosaminidase). Similarly, regression of hypertrophy after return to normal salt intake and cessation of DOCA was unaccompanied by any changes in the enzymes. These results suggest that significant changes in lysosomal function are not an important feature of the development or regression of cardiac hypertrophy induced by systemic hypertension.     

Chloroquine-induced lysosomal abnormalities in cultured foetal mouse hearts

Chloroquine (100 μm) induces abnormalities of lysosomal structure in cultured mouse hearts. After 1 or 2 days' exposure to the drug, large autophagic vacuoles with myeloid figures and inclusion bodies develop within myocytes and interstitial cells. Secondary lysosomes in interstitial cells occasionally contain cardiac myofilaments. In addition, after 2 days, the amounts of cathepsin D and β-acetylglucosaminidase decrease significantly, along with a significant redistribution of enzyme activity between sedimentable and non-sedimentable fractions. The results suggest that chloroquine is a useful experimental agent for causing lysosomal derangements in cardiac tissues under controlled conditions.     

硒对缺氧培养乳鼠心肌细胞存活率和膜流动性的影响

采用Ｌａａｒｓｅ等培养乳鼠心肌细胞的方法，观察加入不同剂量的亚硒酸钠对“缺氧”心肌细胞成活率及其膜流动性的影响。结果表明：适量硒（１×１０－６ｍｏｌ／Ｌ）可增加细胞存活率及膜流动性，而过量硒（１×１０－５ｍｏｌ／Ｌ）使细胞存活率及膜流动性下降。结论：适量硒对缺氧培养的心肌细胞有保护作用，过量硒具有明显的细胞毒性作用     

硒对大鼠心电图及心肌细胞动作电位的影响

目的　探讨硒对大鼠心电图及心肌细胞动作电位的影响。方法　对Ｗ ｉｓｔａｒ雄性大鼠腹腔内注射亚硒酸钠（２ｍ ｇ·ｋｇ－１·ｄ－１）,连续９ 周,应用心电图和细胞内玻璃微电极技术,观察正常大鼠和阿霉素致心肌损伤大鼠心电图及心肌细胞动作电位的变化。结果　硒组心电图较实验前及对照组无变化（ Ｐ ＞ ０．０５ ）,心肌细胞复极达峰值电位５０％ 所需时间（ＡＰＤ５０）延长（ Ｐ ＜ ０．０５ ）。ＡＤＭ 组和硒＋ ＡＤＭ 组心电图Ｑ－Ｔ 间期及心肌细胞ＡＰＤ５０、ＡＰＤ９０较对照组及试验前均延长（ Ｐ＜ ０．０１）。心率、静息电位（ＲＰ）、动作电位幅度（ＡＰＡ）及动作电位０ 相最大去极化速率（Ｖｍ ａｘ）无变化（ Ｐ ＞ ０．０５）。结论　硒能延长正常大鼠心肌细胞ＡＰＤ５０,不能逆转阿霉素心肌损伤大鼠ＡＰＤ５０、ＡＰＤ９０及Ｑ—Ｔ 间期延长。此结果对于心肌病的防治具有重要意义。     

Lysosomal alterations in autolyzing rabbit heart.

Sequential biochemical and immunohistochemical lysosomal alterations were assessed in autolyzing ventricular myocardium incubated at 37°C in a humidified atmosphere for 15 min to 2 h. A profound redistribution of cathepsin D activity into the nonsedimentable fraction of homogenates could be demonstrated after only 15 min of autolysis, with further increases over the next 105 min. Nonsedimentable activity of n-acetyl-β,d-glucosaminidase was also significantly increased early after the onset of autolysis, but the distribution of acid phosphatase activity was not significantly altered. Immunohistochemical localization of cathepsin D revealed dramatic loss of granular staining in myocytes during the first hour of autolysis. Between 15 and 30 min, lysosomes became enlarged and halos of fluorescent material appeared, representing diffusion of cathepsin D from lysosomes into the myoplasm. By 60 min most cathepsin-D-positive organelles had vanished and the enzyme was instead distributed diffusely throughout the cell. The early redistribution of cathepsin D observed by biochemical and immunohistochemical techniques occurred before electron microscopic indications of cell death became apparent. Thus, autolyzing heart may provide a useful model for studying the possible role of lysosomal enzymes in provoking myocardial cell injury and necrosis.     

硒缺乏实验性心肌病的电显细胞化学研究

本文用低硒半合成饲料和补硒合成饲料喂养大鼠,喂养8和12周后分别处死。对心肌标本作常规电镜和细胞化学(细胞色素氧化酶、酸性磷酸酶和 Ca~( )ATP 酶)检查。实验结果表明硒缺乏可引起心肌下述主要改变,心肌膜系呈现不同程度损伤;心肌氧化磷酸化障碍,氧利用降低,ATP 合成减少;某些细胞器内 ATP 依存性钙的调控运转异常,从而进一步导致细胞器和收缩成分的一系列改变。     

艾通立对急性缺血性心肌损伤大鼠血液流变学异常的干预

目的:探讨重组组织型纤溶酶原激活剂(recombinant tissue plasminogen activator,rt-PA)艾通立(Actil-yse)对急性缺血性心肌损伤(AI MI)大鼠血液流变学异常的干预作用。方法:异丙肾上腺素腹腔注射诱导SD大鼠发生AI MI。设AI MI组、AI MI 艾通立腹腔注射组及正常对照组,检测三组大鼠的血液流变学指标及血浆内皮素(ET)浓度。结果:与正常对照组相比,AI MI组各项血液流变学指标及血浆ET浓度均显著增高(P<0.01);而艾通立腹腔注射可部分逆转上述改变(P<0.01),且各项血液流变学指标与血浆ET浓度之间呈显著相关(r=-0.5~ 0.98,P<0.01)。结论:艾通立作为rt-PA类药物,可通过对急性缺血性心肌损伤局部血流变学异常的干预,以减轻心肌急性缺血性损伤的程度。