基于胰高血糖素样肽1受体及其下游信号探讨有氧运动对小鼠心梗模型心功能康复的影响

目的:探讨有氧运动训练(AET)对心肌梗死(MI)小鼠的心脏保护作用,并阐明其作用机制是否与胰高血糖素样肽1受体(GLP-1R)激活有关.方法:在实验1(研究AET对MI小鼠的心脏保护作用及对心脏组织中GLP-1R表达的影响)中,67只小鼠分为3组:假手术(sham)组(n=14)、MI组(n=28)和MI+AET组(...     

天麻素预处理对大鼠离体心脏缺血/再灌注损伤的保护作用

目的探讨天麻素对大鼠离体心脏缺血/再灌注(I/R)损伤的保护作用。方法 60只SD雄性大鼠随机分为正常对照组、缺血/再灌注组、天麻素预处理(10、50、100、200μmol/L)组,应用Langendorff离体心脏灌注系统建立心脏I/R损伤模型。除正常对照组外,各组分别进行平衡灌注、全心停灌/再灌处理,从心功能各项指标、心肌酶学、心肌梗死面积(TTC染色)及组织病理学(HE染色)变化4个层面评估天麻素预处理对大鼠离体心脏(I/R)损伤的影响,评价不同浓度天麻素预处理对心脏(I/R)损伤心肌的保护作用。结果与缺血/再灌注组相比,不同浓度天麻素预处理组均可改善缺血/再灌注损伤心功能的各项指标,包括左心室发展压(LVDP)、左室内压上升/下降最大速率(±dp/dtmax)和心率(HR);并降低冠脉流出液中肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、乳酸脱氢酶(LDH)和肌钙蛋白(Trop-I)的活性,有效减少心肌梗死面积,其中以100μmol/L浓度的天麻素效果最显著(P0.05)。结论天麻素预处理对大鼠离体心脏缺血/再灌注引起的心肌损伤有保护作用,其中以100μmol/L的保护作用最为显著。     

心房钠尿肽对缺血再灌注损伤心肌的保护作用及其机制探讨

<正>目的:研究心房钠尿肽(atrial natriuretic peptide,ANP)对缺血再灌注损伤心肌的保护作用及其作用机制。方法:SD大鼠随机分为正常组、对照组及ANP组;通过Langendorff灌流装置建立大鼠离体心脏缺血再灌注模型,计算出各组缺血心脏的梗死面积,并利用化学比色法测定各组心脏组织中乳酸(LD)、超氧化物歧化酶(SOD)活性以及丙二醛(MDA)含量。结果:ANP     

Hexarelin对心脏功能调节的研究进展

生长素释放肽(GHRP)是一种人工合成的促使垂体生长素的释放的促分泌肽类物质,对心脏有与生长素类似的作用。它对于心脏的作用主要是通过存在于心脏的一种特殊的受体介导的,而且与其促生长素释放的作用无关。海沙瑞林(Hexarelin)是一种高度稳定的GHRP修饰物。近些年的国内外实验研究表明Hexarelin对心脏具有较为全面的保护和调控作用;可以有效的减少心肌细胞Ca2+的转运并调控收缩耦联过程,增强心肌细胞对Ca2+的调控作用;可以控制血管高反应性,对心肌缺血损伤有相应的的保护作用;Hexarelin可以促进心肌细胞损伤后的修复,而且具有抑制心肌细胞凋亡作用;Hexarelin能有效的升高每搏输出量、增加心脏收缩能力和心脏指数,延缓心脏恶病质的进程发展,体现了对心脏的正性肌力作用。本文综述了Hexarelin对心脏作用的研究进展及在临床心血管疾病的治疗上的良好应用前景。     

甘氨酸对内毒素所致心肌损伤的影响

目的探讨甘氨酸对内毒素所致心肌损伤的保护作用.方法采用Langendord装置,应用Krebs-Henseleit(KH)液行主动脉逆灌注,动态观察离体心脏单相动作电位(MAP)和心肌张力曲线,并在实验的0、20、50、80min收集灌流液,测定其中超氧化物歧化酶(SOD)、丙二醛(MDA)、乳酸脱氢酶(LDH)、磷酸肌酸激酶(CK)、一氧化氮(NO)等的含量.结果甘氨酸处理组对内毒素诱导心脏单相动作电位的D20、D50和心率等的变化有一定改善作用,但对心肌张力曲线的改善不明显,对内毒素诱导的SOD活性降低和MDA含量升高有抑制作用,可以减缓和降低心肌损伤引起的LDH和CK的释出,并且降低NO的释放等.结论甘氨酸可以减轻内毒素所致心肌损伤、改善心脏功能状态,其作用机制可能与甘氨酸拮抗内毒素的作用及甘氨酸对血管内皮细胞、心肌细胞的保护作用有关.     

羟苯氨酮保护麻醉猫心对抗缺血与再灌注损伤

目的确定羟苯氨酮对在体心脏缺血-再灌注损伤的对抗作用。方法建立麻醉猫心冠脉前降支阻断30 min,再灌60 min的模型,从心脏血流动力学、心外膜心电图(Epi-ECG)、心肌能量代谢、血清丙二醛(MDA)含量、肌酸磷酸激酶(CPK)与谷草转氨酶(GOT)活性等方面评价羟苯氨酮的保护作用。结果静注羟苯氨酮2.0~8.4 mg/kg剂量依赖性地减慢心率(HR),降低血压(MAP)、心脏作功和外周血管阻力(SVR),减轻以Epi-ECG ST段升高为指标的心肌缺血反应,对抗再灌注引起的缺血区心肌三磷酸腺苷(ATP)与磷酸肌酸(PCr)含量及ATP/Pi、PCr/Pi比值减少和血清MDA含量、CPK与GOT活性升高,并使之保持在正常水平。结论羟苯氨酮明显保护在体心脏对抗心肌缺血-再灌注损伤。     

缺血预处理前加用腺苷对未成熟兔心肌再灌注损伤的影响

目的和方法:建立3-4周龄幼兔离体心脏左心作功模型,心脏缺血期间均间断灌注心脏停搏液,研究缺血预处理前加用腺苷对未成熟兔再灌注心肌的保护作用并探讨其机制。结果:再灌注期,缺血预处理前加用腺苷的心脏的左室收缩压(LVSP)、左室舒张末压(LVEDP)、左室内压上升最大速率(+dp/dt_max)和左室内压下降最大速率(-dp/dt_max)恢复最佳,肌酸激酶(CK)漏出率低,心肌组织丙二醛(MDA)含量低、超氧化物歧化酶(SOD)活性高,心肌组织三磷酸腺苷和二磷酸腺苷(ATP+ADP)含量高;心肌含水量(MWC)低。结论:缺血预处理前加用腺苷能强化缺血预处理对未成熟兔再灌注心肌的保护作用。     

川芎嗪对缺血再灌注所致大鼠离体心脏损伤的保护作用

目的:观察川芎嗪对缺血再灌注所致大鼠离体心脏损伤的保护作用。方法:心脏缺血再灌注模型:大鼠离心脏Langen-dorff灌流,全心停灌20分钟后复灌40分钟造成缺血--再灌注损伤。将充水乳胶球囊通过左心房插入左心室,Medlab-u/81生物信号采集处理系统记录分析心功能指标LVP,±dp/dtmax,HR和CF,收集再灌5分钟时,冠脉流出液。用分光光度法测定肌酸激酶(CK)活性。结果:缺血再灌注能降低冠脉流量,LVP,±dp/dtmax值,减慢心率、增加CK释放量,两个浓度的川芎嗪(40与80mg·L-1)对离体大鼠心脏缺血再灌注损伤有保护作用,表现为改善心功能,增加冠脉流量,减少心肌细胞内酶CK的释放,川芎嗪与维拉帕米有相似的心肌保护作用。结论:川芎嗪对心脏缺血再灌注心功能损伤具有保护作用。     

短期运动对大鼠缺血/再灌注心肌的保护作用

目的研究短期中等强度运动训练对大鼠缺血/再灌注(I/R)心肌的保护作用及与蛋白激酶C(PKC)激活的相关性。方法40只Wistar大鼠随机分为4组(每组10只):对照组(CON组)、运动组(EXE组)、运动 PKC抑制剂组(E C组)和PKC抑制剂组(CHE组)。应用Langendorff离体心脏I/R模型,观察各组大鼠心脏再灌注期间心律失常的发生情况、心功能指标恢复率及心肌梗死范围。结果EXE组大鼠LVDP(再灌注30、60 min)和RPP(再灌注20、30、60 min)恢复率高于CON和E C组(P<0.05或P<0.01),心肌梗死范围显著低于CON和E C组(P<0.01)。CON、CHE组上述各指标无差异。结论短期中等强度运动训练对I/R心肌有保护作用,保护作用与PKC的激活有关。     

松弛素的心血管调节作用

松弛素 (RLX)是体内存在的妊娠激素 ,其在心血管系统也发挥重要的作用。RLX是一种新的心血管保护因子 ,在充血性心衰、缺血再灌注损伤及心脏纤维化等多种心血管病的防治中扮演重要角色 ,对心脏有正性变时和变力作用。     

雷公藤甲素抗肿瘤血管新生的研究进展（英文）

雷公藤甲素(triptolide,TPL)是从中草药雷公藤中提取的一种有效活性物质,已被用来治疗多种疾病,包括系统性红斑狼疮,类风湿性关节炎,肾病综合征等,TPL甚至有很强的抑制肿瘤的活性。近些年的研究显示,TPL具有抗血管新生的能力,TPL不仅可以抑制肿瘤的增殖,诱导细胞的凋亡,还可以抑制肿瘤的转移,可以增加其它化疗药物的抗肿瘤活性。本综述将讨论TPL在抗肿瘤血管新生方面的研究进展,以及初步探讨其潜在的作用机制。     

Changes in activity of neutral proteases in tissues of ground squirrels in the dynamics of hibernation

Total activities of neutral proteases in the cerebral, hepatic, and myocardial tissues of ground squirrel vary during hibernation: in autumn (before hibernation) activities of the enzymes in the brain and myocardium start increasing, while in the liver they do not change. A common feature for all tissues is minimum activity of active neutral proteases in the middle of hibernation month 1 bout, while the maximum activity is recorded before awakening. Translated from Byulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 146, No. 9, pp. 278–280, September, 2008     

Kinetics of decline of maternal measles virus-neutralizing antibodies in sera of infants in France in 2006

The optimal age for measles vaccination is an important health issue, since maternal antibodies may neutralize the vaccine antigen before a specific immune response develops, while delaying vaccination may increase the risk of complicated diseases in infants. However, measles vaccination impacts the duration of protection afforded by transplacental transfer of maternal antibodies: vaccination-induced maternal antibodies disappear faster than disease-induced antibodies. In order to maintain protection against measles in infants, it is important to monitor the dynamics of this phenomenon in vaccinated populations. To assess the current situation in France, a multicenter, prospective seroepidemiological study was conducted in seven French hospitals between October 2005 and January 2007. Maternal measles antibody concentrations from 348 infants 0 to 15 months old were measured using the plaque reduction neutralization assay. Geometric mean concentrations and the percentage of infants with maternal measles antibody concentrations above the protection threshold (≥120 mIU/ml) were assessed according to age. Results show that after more than 20 years of routine measles vaccination in France, maternal measles-neutralizing antibodies decrease dramatically in French infants by 6 months of age, from 1,740 mIU/ml for infants 0 to 1 month old to 223 mIU/ml for infants 5 to 6 months old, and that 90% of infants are not protected against measles after 6 months of age. Infant protection against measles could be optimized both by increasing herd immunity through an increased vaccine coverage and by lowering the age of routine vaccination from 12 to 9 months.     

Effect of vitamin C in reducing the toxicity of endosulfan in liver in rabbits

In this study, the effect of endosulfan, an organochlorine pesticide, and the ameliorating effect of vitamin C on the livers of New Zealand white rabbits were studied. Livers of the rabbits were examined grossly and histopathologically, and caspase-3 activity was detected by immunohistochemical methods. A total of twenty-four rabbits were divided into four groups (n=6). Rabbits in Group I (END) were daily given a sublethal dose of endosulfan (1 mg/kg bw) in corn oil by oral gavage for 6 weeks. Group II (END+C) received the same dose of endosulfan and additionally Vit C (20 mg/kg bw) every other day during this period. Group III (OIL+C) received corn oil daily by oral gavage and vitamin C every other day for 6 weeks. Group IV (OIL), the control group, received only corn oil daily, by oral gavage throughout the experiment. The concentration of α-endosulfan in the END group was higher in livers (0.102±0.012 ppb) than the β-endosulfan (0.072±0.001 ppb). Decreased accumulation of α and β endosulfan was observed in the END+C group (0.025±0.003 and 0.016±0.002 ppb, respectively) (p<0.0001). The most prominent gross findings at the necropsy were seen in the END group, in which swollen and pale livers were commonly observed. Hemorrhages, degenerations, necrosis, and in some rabbits bile duct hyperplasia were the marked histopathological findings of the END group. Caspase-3 positive reaction was more severe in this group than in the others. An ameliorating effect of Vit C on gross, histopathological and immunohistochemical findings was observed in the END+C group. The results revealed that endosulfan is highly toxic for rabbit livers. However, toxicity was decreased by Vit C treatment, which reduced the accumulation of endosulfan in livers four-fold.