外源性5—羟色胺对心肌细胞生长及其受体表达的影响

目的：研究外源性5－羟色胺（5－HT）对心肌细胞生长及5－HT受体表达的影响，以探讨5－HT在心肌肥厚发生中的作用。方法：采用乳鼠心肌细胞培养和免疫组织化学方法评价5－HT的作用。结果：大鼠心室肌细胞膜上有5－HT受体分布，外源性5－HT（10μmol.L^-1)可促进其表达；细胞增殖实验发现5－HT在1μmol.L^-1，10μmol.L^-1和100μmol.L^-1时均显著促进心肌细胞蛋白质和DNA合成及心脏成纤维细胞增殖，以10μmol.L^-1剂量时作用最强，但作用强度弱于同浓度去甲肾上腺素。结论：心肌细胞膜上有5－HT受体分布，外源性5－HT可促进其表达，外源性5－HT中促进心肌细胞和成纤维细胞增殖，可能参与心肌肥厚的发生发展过程。     

5-羟色胺受体药物与胃肠疾病

5-羟色胺(5-HT)是重要的肠神经介质,其代谢变化与某些胃肠疾病密切相关。研究发现5-HT受体桔抗剂与激动剂对部分胃肠功能性疾病疗效较好。本文扼要综述5-HT_3受体拮抗剂、5-HT_4受体激动剂与拮抗剂在胃肠疾病中的作用机制及临床疗效。     

肺动脉高压的5-羟色胺/5-羟色胺转运体机制研究进展

肺动脉高压是临床常见的以肺血管阻力进行性增加并伴有不可逆的血管构型重塑为特征的疾病.5-羟色胺作为一种血管活性物质,可以通过5-羟色胺转运体介导,诱导肺动脉平滑肌细胞增殖,促进肺中小动脉构型重塑.因此,揭示5-羟色胺及5-羟色胺转运体在肺动脉高压形成发展中的重要作用,探讨其成为抗肺动脉高压药物治疗新靶点的可能性具有重要意义.     

5-羟色胺及其受体研究进展

5-羟色胺（5-HT）是一种吲哚衍生物，最早在血清中发现，又名血清素，广泛存在于哺乳动物中，且在大脑皮层和神经突触内含量高，是一种抑制性神经递质。在外周组织中，5-HT是一种强血管收缩剂和平滑肌收缩刺激剂。5-HT可以经单胺氧化酶催化成5-羟色醛和5-羟吲哚乙酸，随尿液排出体外。     

健脾化湿颗粒对腹泻型肠易激综合征大鼠结肠5-羟色胺、5-羟色胺3受体的影响

目的探讨健脾化湿颗粒对腹泻型肠易激综合征(D-IBS)模型大鼠结肠中5-羟色胺(5-HT)和5-羟色胺3受体(5-HT3R)水平的影响。方法选用60只SD雄性大鼠,按体重随机分成六组,分别为正常组,模型组,健脾化湿颗粒低、中、高剂量组,阳性对照组。采用酶联免疫吸附法(ELISA)检测大鼠结肠黏膜中5-HT含量,采用免疫组化法检测结肠黏膜下5-HT3R阳性细胞的表达量,采用逆转录聚合酶链反应(RT-PCR)法检测结肠中5-HT3R mRNA的表达水平。结果与正常组相比,模型组结肠中5-HT水平显著升高(P0.05),结肠黏膜下层5-HT3R阳性细胞的含量明显升高(P0.05),结肠中5-HT3R mRNA的表达水平亦显著升高(P0.05);健脾化湿颗粒可以降低5-HT水平,5-HT3R水平及其mRNA表达量。结论健脾化湿颗粒可能通过降低结肠黏膜5-HT含量,减少结肠5-HT3R的表达量,减弱5-HT3R神经元兴奋性,从而改善内脏痛觉敏感状态,消除肠道反应。     

系统性红斑狼疮患者血清5-羟色胺水平及其受体在CD8+T细胞表达的研究

目的 探讨系统性红斑狼疮(SLE)患者血清5-羟色胺(5-HT)及其受体[5-羟色胺2A受体(5-HT2AR)和5-羟色胺7受体(5-HT7R)]在CD8+T细胞的表达.方法 选取2019年8月至2020年10月在中国医科大学附属第一医院风湿免疫科住院的SLE患者35例及健康对照(HC)者30例,比较两组间血清5-HT...     

胃起搏对大鼠胃窦肌间神经丛5-羟色胺能神经的影响

背景:胃起搏治疗胃动力障碍性疾病已引起广泛关注,但其作用机制尚不清楚。目的:观察胃起搏后胃窦肌间神经丛5-羟色胺(5-HT)能神经的活性变化,探讨胃起搏促胃动力作用的神经化学机制。方法:建立Wistar大鼠胃起搏模型,将大鼠分为起搏组(n=10)和对照组(n=6)。选用适宜的起搏参数以控制起搏组胃电慢波,1h后取胃窦组织,以免疫组化方法结合图像分析技术分析5-HT免疫反应阳性产物的分布、数量和免疫反应强度。结果:对照组大鼠5-HT免疫反应阳性神经纤维以肌间神经丛和节间束中稍多,神经节内阳性神经细胞体少见。起搏组大鼠胃窦组织5-HT免疫反应阳性神经纤维较对照组明显增多,神经节内阳性神经细胞体和带膨体的神经纤维也明显增多,免疫反应增强;肌间神经丛5-HT免疫反应阳性产物面积和平均光密度值均显著高于对照组(P<0.001)。结论:胃起搏后,胃窦肌间神经丛5-HT免疫反应阳性神经纤维和神经细胞体分布增多,5-HT能神经活性增强,表明5-HT能神经可能参与了胃起搏的促胃动力作用。     

癫痫发病与脑内5-羟色胺及其受体相关

癫痫是一组由已知或未知病因引起．脑部神经元高度同步化且常具有自限性的异常放电所导致，以反复发作性、短暂性、通常为刻板性的中枢神经系统功能失常为特征的综合征。癫痫是神经系统疾病中的一种常见病．     

内脏高敏感大鼠结肠5-羟色胺转运体蛋白的表达

目的:探讨5-羟色胺转运体蛋白(SERT)在内脏高敏感性中的作用,为功能性胃肠病的发病机制研究提供理论基础.方法:采用乳鼠醋酸灌肠建立大鼠慢性内脏高敏感动物模型,同时设立对照组.待乳鼠成年后应用直肠内球囊扩张评估腹壁撤离反射(AWR)的方法,评估其内脏敏感性;检测髓过氧化物酶(MPO)评价其肠道黏膜炎症程度;用RT-PCR方法评价大鼠结肠SERT的mRNA水平,免疫组织化学方法评价大鼠结肠SERT的表达:用ELISA方法检测血浆和结肠组织5-HT水平.结果:乳鼠醋酸灌肠建立的大鼠慢性内脏高敏感模型组与对照组相比HE染色显示结肠黏膜未见明显急、慢性炎症改变;两组大鼠结肠组织MPO水平没有显著性差异;在不同容量下的AWR评分慢性内脏高敏感模型组显著高于对照组(P<0.01).血浆5-HT水平慢性内脏高敏感模型组明显高于对照组(95.75±15.99vs 72.17±8.01,P<0.01),而两组结肠组织5-HT含量没有明显差异.免疫组织化学研究显示内脏高敏感模型组结肠上皮SERT表达水平显著低于对照组(0.187±0.010 vs 0.191±0.011,P<0.011,而其结肠SERT mRNA水平显著高于对照组(16.02±3.7 vs 10.05±2.12,P<0.01).结论:内脏高敏感大鼠外周5-HT水平的增高主要来源于其灭活的减少而非合成的增加,与SERT的关系密切.结肠SERT可能具有不同的亚型和功能.     

心钠素及内皮素对心肌细胞肥大及心脏成纤维细胞增殖的影响

目的观察心钠素(ANP)、内皮素-1(ET-1)对心肌细胞肥大和心脏成纤维细胞增殖的调节作用。方法采用体外乳鼠心肌细胞和心脏成纤维细胞培养,一定浓度的ET-1、ANP单独或联合作用细胞24h,以3H-胸腺嘧啶脱氧核苷(3H-TdR)、3H-亮氨酸(3H-Leu)掺入法测定细胞DNA、蛋白合成,Brad-ford法测细胞总蛋白含量,RT-PCR法测心肌细胞心钠素ANPmRNA的表达,评价ET-1、ANP对心肌细胞和成纤维细胞的作用。结果对于心肌细胞,ET-1显著促进3H-TdR、3H-Leu掺入,总蛋白含量增加,呈剂量依赖性,ANPmRNA表达明显增加;对于心脏成纤维细胞,ET-1促进3H-TdR、3H-Leu掺入,总蛋白含量增加,以上作用可被ANP明显抑制。结论ET-1促进ANP分泌的同时也促进心肌细胞肥大和心脏成纤维细胞增殖,ANP反之抑制ET-1的促心肌肥厚作用。     

腹泻型肠易激综合征患者结肠黏膜5-羟色胺和5-羟色胺3受体的研究

背景：肠易激综合衙（IBS）是一种功能性胃肠道疾病，其病因和发病机制迄今尚未完全阐明。目的：探讨5-羟色胺（5-HT）和5-HT3受体（5-HT3R）在腹泻型IBS（D—IBS）患者结肠黏膜中的变化及其临床意义。方法：对18名正常人和28例D—IBS患者行结肠镜检查并分别取升结肠、横结肠、降结肠和乙状结肠黏膜标本各两块。以免疫组化方法检测5-HT阳性细胞；以蛋白质印迹分析半定量检测5-HT3R的表达。结果：D—IBS组4个部位结肠黏膜的5-HT阳性细胞数和5-HT3R的表达均较正常对照组显著增多（P〈0．05），但4个部位之间相互比较均无显著差异。结论：D—IBS患者结肠黏膜5-HT合成和分泌增多，5-HT3R表达上调，提示5-HT和5-HT3R可能为D—IBS的分子生物学基础之一，为D—IBS的治疗提供了分子靶点。     

心钠素及内皮素对心肌细胞肥大及心脏成纤维细胞增殖的影响

目的观察心钠素(ANP)、内皮素-1(ET-1)对心肌细胞肥大和心脏成纤维细胞增殖的调节作用.方法采用体外乳鼠心肌细胞和心脏成纤维细胞培养,一定浓度的 ET-1、ANP单独或联合作用细胞24 h,以3H-胸腺嘧啶脱氧核苷(3H-TdR)、3H-亮氨酸(3H-Leu)掺入法测定细胞DNA、蛋白合成,Bradford法测细胞总蛋白含量,RT-PCR法测心肌细胞心钠素ANP mRNA的表达,评价ET-1、ANP对心肌细胞和成纤维细胞的作用.结果对于心肌细胞,ET-1显著促进3H-TdR、3H-Leu掺入,总蛋白含量增加,呈剂量依赖性,ANP mRNA表达明显增加;对于心脏成纤维细胞,ET-1促进3H-TdR、3H-Leu掺入,总蛋白含量增加,以上作用可被ANP明显抑制.结论ET-1促进ANP分泌的同时也促进心肌细胞肥大和心脏成纤维细胞增殖,ANP反之抑制ET-1的促心肌肥厚作用.     

Effects of Olmesartan, an Angiotensin II Receptor Blocker, on Mechanically-Modulated Genes in Cardiac Myocytes

Background: Angiotensin II plays an important role in cardiac hypertrophy or remodeling. Angiotensin II receptor blockers (ARB) are clinically useful for the treatment of hypertension and heart failure. However, the molecular effects of ARB in the mechanically-stressed myocardium have not been completely defined. We investigated the effects of ARB on mechanically-modulated genes in cardiac myocytes. Methods: We used powerful DNA microarray technology to study the effects of the ARB, CS-886 (olmesartan), on genes modulated in neonatal rat cardiac myocytes using mechanical stimuli. Mechanical deformation was applied to a thin and transparent membrane on which neonatal rat cardiac myocytes were cultured in the presence or absence of RNH-6270, an active metabolite of CS-886. Expression profiles of 8000 rat genes using the Affymetrix GeneChip (Rat Genome U34A) were investigated with mRNA obtained from the samples above. Results: Nine genes induced under 4% mechanical strain were significantly suppressed by RNH-6270 in rat cardiac myocytes: monoamine oxidase B, neuromedine B receptor, olfactory receptor, synaptotagmin XI, retinol-binding protein, and 4 expressed sequence tags (ESTs). In contrast, 21 genes suppressed under mechanical strain were significantly restored by RNH-6270: major acute phase alpha 1-protein, Sp-1, Bcl-Xalpha, JAK2, 2 genes encoding detoxification, few genes for receptor, structure, metabolism or ion channel, and 10 ESTs. Conclusions: As some of these genes may be involved in promoting or modulating cardiac remodeling, these findings suggest that ARB may affect cardiovascular morbidity and mortality partially via these molecular alterations.     

Effects of β-Adrenergic Receptor Activation on Intracellular Calcium and Membrane Potential in Adult Cardiac Myocytes

β-Adrenergic Receptor Activation and Intracellular Ca²⁺. Introduction:β-Adrenergic receptor agonists have been shown to increase the voltage-dependent Ca²⁺ current in cardiac myocytes. Additionally, adrenergic receptor activation has been shown to increase intracellular Ca²⁺, to increase systolic Ca²⁺ transients and to enhance Ca²⁺ uptake into the sarcoplasmic reticulum, thereby accelerating relaxation. The present study was designed first to characterize the influences of β-adrenergic receptor activation on intracellular Ca²⁺ activity as well as membrane potential in ventricular myocytes characterized as normal based on rigorous morphologic and electrophysiologic criteria. The second objective was to assess whether the increase in intracellular Ca²⁺ activity elicited by β-adrenergic receptor activation could elicit afterdepolarizations and triggered activity. Methods and Results: Intracellular Ca²⁺ and whole-cell voltage recordings were measured in cells in which indo-1 free acid was delivered intracellularly through the recording pipette. Isoproterenol produced complex Ca²⁺ transients underlying both early and delayed afterdepolarizations during pacing as well as aftertransients underlying triggered action potentials and delayed afterdepolarizations in the absence of pacing. The coupling interval of Ca²⁺_i aftertransients was frequency dependent and followed that of the delayed afterdepolarizations. Ca²⁺_i after transient amplitudes, however, exhibited a biphasic response with frequency revealing that factors other than pacing frequency alone contribute to control of the amplitude of the aftertransients. Inhibition of sarcoplasmic reticular release of Ca²⁺ by ryanodine abolished Ca²⁺_i aftertransients and afterdepolarizations otherwise elicited by isoproterenol. Conclusion: These data demonstrate that normal cells stimulated by β-adrenergic agonists exhibit marked changes in intracellular Ca²⁺ homeostasis that may serve as the substrate for abnormal ion fluxes that ultimately contribute to electrophysiologic derangements underlying arrhythmogenesis in the intact heart. (J Cardiovasc Electrophysiol, Vol. 3, pp. 209–224, June 1992)     

心脏肾上腺素受体及其自身抗体研究进展

作为交感神经递质的去甲肾上腺素(norepinephrine,NE)及内分泌激素的肾上腺素(adrenaline,Ad)参与体内多数器官功能的调节,而这种调节都要通过靶器官上的肾上腺素受体(adrenergic receptor,AR)来实现。此外,在所有G蛋白耦联的膜表面受体中,AR是目前相对了解最清楚的一种,因而AR又可作为研究整个G蛋白耦联受体家族的一个理想模型。自Friou(1957年)等首先在系统性红斑狼疮(systemic lupus erythematosus,SLE)病人血清中发现抗核抗体(anti-nuclear antibody,ANA)以来,人们在自身免疫性疾病,心脏病病人甚至健康人血清中检测出越来越多的抗不同抗原的自身抗体,并对其功能进行了一些研究。现综述近年来AR及其自身抗体的研究进展。     

血管紧张素Ⅱ及血管紧张素Ⅱ 1型受体反义寡核苷酸对心肌细胞bax、bcl-2基因表达

目的探讨血管紧张素(Ang Ⅱ)及血管紧张素Ⅱ 1型受体(AT1R)反义寡核苷酸(AS-ODN)对心肌细胞凋亡调节蛋白bax、bcl-2的影响.方法将培养的乳鼠心肌细胞分为正常组、AngⅡ组、AT1R-AS-ODN组 Ang Ⅱ组用10-6mol/L Ang Ⅱ刺激24小时;AT1R-AS-ODN组在转染反义寡核苷酸后也用10-6mol/L Ang Ⅱ刺激24小时;正常组不予任何刺激.刺激24小时后用免疫细胞化学方法观察Ang Ⅱ及AT1R-AS-ODN对心肌细胞凋亡调节蛋白bcl-2、 bax表达的影响.结果与正常组相比,AngⅡ组心肌细胞bcl-2蛋白光密度值下降显著(0.0725±0.0065 vs 0.0975±0.0083, P<0.05),bax蛋白光密度值增加(0.0941±0.0042 vs 0.0823±0.0024, P<0.05);与Ang Ⅱ组相比,AT1R-AS-ODN组bcl-2蛋白光密度值增加(0.0900±0.0016 vs 0.0725±0.0065, P<0.05),bax蛋白光密度值降低(0.0863±0.0019 vs 0.0941±0.0042, P<0.05).结论 Ang Ⅱ可以诱导心肌细胞发生凋亡,而AT1R-AS-ODN可以逆转Ang Ⅱ诱导的心肌细胞凋亡.     

V1受体拮抗剂对精氨酸升压素诱导的大鼠心脏成纤维细胞增殖的影响

目的探讨V1受体拮抗剂[d(CH2)5-Tyr2(Me)]AVP对精氨酸升压素(AVP)诱导的大鼠心脏成纤维细胞增殖的影响. 方法采用胰酶消化法培养新生Sprague-Dawley (SD)大鼠心脏成纤维细胞(CFs),以3H-TdR掺入法测定CFs的DNA合成功能,MTT比色法测定CFs数目,并应用流式细胞仪进行CFs细胞周期分析. 结果①CFs的3H-TdR掺入率随着AVP干预浓度的增加而增高,其中10-7mol/L AVP和10-6mol/L AVP组每5000个细胞的3H-TdR掺入率分别为(243±61)cpm和(328±68)cpm,均明显高于对照组3H-TdR掺入率(117±32)cpm(P<0.01);②MTT比色法吸光度(A490 nm)值随AVP浓度的增加而增高,其中10-7mol/L AVP、10-6mol/L AVP组的A490 nm值分别为0.24±0.01和0.29±0.02,均较对照组A490 nm值(0.16±0.01)显著增高(P<0.01);③10-7mol/L AVP组CFs细胞周期S期百分率显著高于对照组(30.20±0.88)% vs (26.86±1.06)%( P<0.01);④10-7mol/L AVP+10-7 mol/L [d(CH2)5-Tyr2(Me)]AVP组的每5000个细胞的3H-TdR掺入率、MTT比色法A490 nm值和S期百分率分别为(143±40)cpm、0.17±0.01和(25.02±0.51)%,均显著低于10-7mol/L AVP组(分别P<0.05,P<0.01,P<0.01). 结论 AVP可诱导CFs的DNA合成功能增强和细胞数目增加,其作用可被V1受体拮抗剂[d(CH2)5-Tyr2(Me)] AVP所阻断,表明V1受体可能介导了AVP促CFs增殖效应.     

Electrophysiologic Effects of Interactions Between Activated Canine Neutrophils and Cardiac Myocytes

Effects of Neutrophils on Cardiac Myocytes. Introduction: Myocardial ischemia causes neutrophils to bind to activaled myocytes and liberate platelet-activating factor (PAF). PAF causes delayed repolarization, early afterdepolarizations (EADs), and arrest of repolarization. We studied the effect of activation of neutrophils bound to canine cardiac myocytes to determine if such activation causes PAF generation and similar changes in transmembrane potentials. Methods and Results: Myocytes from canine left ventricle and neutrophils from the same dog were superfused with Tyrode's solution and transmembrane potentials recorded from the former. Neutrophils (100 μL, 10^-6/mL) were added and allowed to bind to the myocytes. Neutrophils were activated with 1% zymosan-activated serum (ZAS). CV-6209 (100 nM) was used to block receptors for PAF. Liberation of PAF by activated neutrophils was quantified with a commercial radioimmunoassay kit. Neutrophils activated with ZAS caused changes in myocyte transmembrane potentials like those induced by PAF: action potential prolongation, runs of EAD, and periods of plateau arrest. PAF receptor blockade prevented neutrophil activation from altering transmembrane potentials. Neutrophils activated with 1 % ZAS liberated significant amounts of PAF. Conclusions: When neutrophils bound to cardiac myocytes are activated by exposure to 1% ZAS, they cause prompt and consistent changes in myocyte electrical activity that could be arrhythmogenic for the in situ heart. These changes are similar to those caused by PAF in pharmacologic studies. Neutrophils activated in this manner generate PAF, and the effects of their activation are prevented by blockade of PAF receptors. We conclude that, during reperfusion of ischemic myocardium, PAF generated by activated neutrophils most likely is a cause of some arrhythmias.