学龄儿童偏头痛与血小板和血浆5-羟色胺关系分析

近年来,偏头痛的发病机制和治疗方面的研究取得很大进展,认为这是一种多灶性疾病。不仅有颅内外血管张力的改变,还有中枢神经系统(CNS)、胃肠道、内分泌、血小板等多方面病理生理改变,并且认为这些改变均可以用体内5-羟色胺(5-HT及其受体异常来解释,所以偏头痛和5-HT的关系重新受到重视。血小板在血栓和止血过程中能够释放5-HT,目前还发现血小板在选择性摄取、贮存、释放、代谢某些单胺类介质和肽类物质方面与中枢神经元具有相同的机制。但有关以血小板作为中枢5-HT能神经元模型进行学龄儿童偏头痛方面的研究,国内尚未见有关报道,现将我们取得的初步结果报道如下。     

外周5-羟色胺在胰岛素抵抗中的作用研究进展

5-羟色胺(5-HT)作为一种神经递质在中枢神经系统中具有重要的作用,同时在外周组织系统中5-HT也发挥多种重要的生物功能,如广泛参与机体的糖脂代谢、肝再生、胃肠运动等。综述外周5-HT诱导胰岛素抵抗的作用机制研究新进展,重点介绍5-HT对胰岛素信号转导、糖脂代谢等方面的影响。     

5-羟色胺受体拮抗剂在肺动脉高压防治中的应用与展望

肺动脉高压是一组由多种病因和发病机制引起的以肺血管阻力进行性增加为特征的病理生理综合征。临床表现为右心室功能不全,预后不良,严重者可发生右心衰竭而死亡。本文主要综述了5-羟色胺与肺动脉高压的关系及5-羟色胺受体拮抗剂在肺动脉高压防治中的作用,展望了5-羟色胺受体拮抗剂可能是一类有潜力的新型治疗肺动脉高压的药物。     

反相高效液相色谱-紫外光检测法测定血浆及血小板中5-羟色胺含量

目的建立反相高效液相色谱-紫外光检测法测定人体血浆及血小板中5-羟色胺(5-HT)的含量。方法样本经处理后,用高效液相-紫外光色谱仪进行检测。色谱柱为Agilent technologies C18(250mm×4.6mm,5μm);流动相为甲醇-0.05mol/L磷酸二氢钾(8∶92);检测波长为275nm;流速为1mL/min。结果5-HT在12.5～0.0244μg/mL浓度范围内与峰面积有很好的线性关系(r=1);高、中、低3个浓度的日内RSD分别是0.41%、0.67%和2.77%;日间RSD分别是0.74%、0.45%和4.03%;血浆中5-HT平均回收率为82.16%,血小板中5-HT平均回收率为88.04%;最低定量限为0.0244μg/mL,最低检测限为0.0122μg/mL。结论用反相高效液相色谱-紫外光检测法测定5-HT简便,快速,特异性好,灵敏度高,重复性好,适用于临床和科研工作。     

人支气管上皮细胞5-脂氧合酶介导4-氨基联苯的活化及DNA损伤

目的探讨人支气管上皮(HBE)细胞内5-脂氧合酶(5-LOX)对4-氨基联苯(4-ABP)的氧化活化及所致DNA损伤,为LOX作为前致癌物氧化活化的代谢途径提供依据。方法①体外酶系统实验:4-ABP在含有大豆脂氧合酶(SLO)的体外酶体系中反应,用分光光度法检测体系中反应产物生成。②细胞实验:4-ABP 100～800μmol.L-1染毒HBE细胞,MTT法检测HBE细胞存活率;Western印迹法检测5-LOX蛋白表达;单细胞凝胶电泳检测DNA损伤。同时,检测特异性5-LOX抑制剂AA861对5-LOX蛋白表达和多种酶抑制剂对细胞存活率和DNA损伤的影响。结果在过氧化氢参与下,SLO可以协同氧化4-ABP,LOX抑制剂去甲二氢愈创木酸可抑制该协同氧化作用。4-ABP可以使HBE细胞内5-LOX蛋白表达增加,AA861对5-LOX蛋白表达没有影响;4-ABP 400μmol.L-1可以使HBE细胞产生明显的DNA损伤,彗星细胞的阳性率达47.7%(P<0.01),AA861和萘普生可以抑制该浓度4-ABP所致的DNA损伤,最大保护率分别为58.1%和21.7%。结论 4-ABP上调HBE的5-LOX蛋白表达。5-LOX可能通过介导4-ABP协同氧化,导致DNA损伤,这可能是4-ABP致癌的机制之一。     

外周5-羟色胺在动脉粥样硬化中的作用研究进展

动脉粥样硬化(AS)是众多心血管疾病的病理基础,研究发现外周5-羟色胺(5-HT)与动脉粥样硬化关系密切.本文综述外周5-羟色胺在动脉粥样硬化发生发展过程中发挥的作用,包括促进巨噬细胞源性泡沫细胞形成,血管平滑肌细胞增殖和迁移,血管收缩,血小板聚集和血栓形成,并总结选择性5-羟色胺2A受体拮抗剂盐酸沙格雷酯在动脉粥样硬化治疗中的应用,以期为动脉粥样硬化研究提供新思路.     

选择性5-羟色胺回收抑制剂在抑郁症治疗中的应用

本文介绍了选择性５＿羟色胺回收抑制剂的作用机制、药物动力学、临床疗效、不良反应和药物相互作用。     

肠嗜铬细胞及其分泌的5-羟色胺在肠易激综合征中的作用

肠易激综合征(irritable bowelsyndrom e,IBS)是一组包括腹痛或腹部不适、排便习惯改变和大便性状异常,持续存在或间歇发作,而又缺乏形态学和生化异常改变可资解释的症候群。按症状大致可以分为腹泻为主型(diarrhea-predom inantIBS,D-IBS)、便秘为主型(constipation-predom inantIBS,C-IBS)、腹泻便秘交替型(alernating IBS,A-IBS)。近十多年来,人们已普遍公认IBS是一种感觉、动力紊乱所致的肠功能性疾病。胃肠运动功能障碍、内脏高敏感性和精神心理因素是IBS最重要的病理生理特征。目前观点认为IBS患者的腹痛、胃肠运动功能…     

花生四烯酸 12-脂氧化酶– 12-氢基二十碳四烯酸– GPR31轴在肝脏再灌注肝缺血损伤中的作用

目的 探究花生四烯酸12-脂氧化酶(ALOX12)–12-氢基二十碳四烯酸(HETE)–GPR31轴在肝脏再灌注肝缺血损伤中的作用机制.方法 采用8周龄雄性B6.Cg-Tg(MX1-cre)Cgn/J小鼠为研究对象,采用随机数字表法分为三组:空白对照组(n=12)、实验对照组(n=12)和实验组(n=12).实验组小鼠进行基于胚胎干细胞的基因打靶技术制备基因敲除手术;进行肝血流阻断.肝血流阻断45 min后发送移走血管夹,以恢复血液供应.实验对照组进行肝血流阻断.空白对照组同样进行开腹但并不进行肝血流阻断.采用蛋白质印迹法(Western blotting)检测ALOX12–12-HETE–GPR31轴中基因表达水平.采用酶联免疫吸附测定(ELISA)法分别检测肝脏血清中白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)三项炎性因子水平和12-HETE含量.采用原位细胞凋亡检测试剂盒检测细胞凋亡情况.采用日立7180全自动生化分析仪检测小鼠肝脏血清中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、AST/ALT.结果 肝脏再灌注肝缺血损伤小鼠的ALOX12–12-HETE-GPR31轴中基因转录水平均高于空白对照组(P<0.05),且随着再灌注时间的延长而逐渐增大(P<0.05).空白对照组和实验组小鼠,在肝血流阻断并再灌注后,随着再灌注时间延长ALOX12–12-HETE–GPR31轴中基因转录水平间差异无统计学意义(P>0.05).实验对照组小鼠肝脏中IL-1β[(20.53±1.32)ng/L比(10.61±0.83)ng/L]、IL-6[(322.1±11.41)ng/L比(107.34±9.02)ng/L]、TNF-α水平[(31.78±2.42)ng/L比(11.41±0.98)ng/L]、12-HETE含量、肝脏组织细胞凋亡率、ALT[(47.94±1.48)U/L比(24.85±1.50)U/L]、AST[(54.45±3.17)U/L比(30.69±2.08)U/L]和AST/ALT[(1.23±0.04)比(0.69±0.03)]均高于空白对照组(P<0.05).实验组小鼠各项指标低于实验对照组(P<0.05),且与空白对照组差异无统计学意义(P>0.05).结论 ALOX12表达量的上调会促进12-HETE的积累,特异性敲除ALOX12基因,阻断12-HETE的积累能够有效抑制肝脏再灌注肝缺血损伤.     

5-羟色胺在胃肠道疾病中的作用及其机制研究进展

5-羟色胺（5-HT）是脑-肠轴途径中一种重要的神经递质,其分泌与肠道菌群、肠道免疫、肠道动力等方面密切相关。5-HT代谢途径异常参与肠易激综合征、炎症性肠病、慢性便秘、功能性消化不良等胃肠道疾病的发生、发展。就5-HT在不同胃肠道疾病中的作用机制研究进行综述,以期为临床治疗开拓新思路。     

Effects of 5-HT released from platelets on thrombin-induced aggregation and ATP release in rabbit pla

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丹酚酸B镁盐对兔洗涤血小板聚集和5-HT释放反应的影响(英文)

AIM: To study the effects and mechanism of magnesium lithospermate B(MLB) on rabbit platelet aggregation and 5-HT release. METHODS: The platelet aggregation was determined by Born's method. Release of serotonin (5-HT) and formation of thromboxane A2 (TXA2) were measured by fluorophotometry and radioimmunoassay (RIA) respectively. Cytoplasmic free Ca2+ concentration ([Ca2+]i) in platelets was measured by Fura 2-AM fluorescence technique. RESULTS: In washed platelets, thrombin (200 U/L) or arachidonic acid (AA) (30 mumol/L)-induced aggregation was inhibited by MLB 50-800 mg/L in a concentration-dependent manner. In addition, MLB had more inhibitory effects on platelet aggregation in the absence of extracellular calcium with IC50 of 102 mg/L than in the presence of CaCl2 1 mmol/L with IC50 of 194 mg/L. MLB concentration-dependently decreased the thrombin-activated release of 5-HT, whereas it did not affect the formation of TXA2 in platelets. Furthermore, MLB not only inhibited the rise of [Ca2+]i in thrombin stimulated platelets, but decreased the [Ca2+]i in resting platelets. CONCLUSION: MLB inhibited the aggregation and 5-HT release in rabbit platelets and it is probably by attenuating intracellular calcium concentration.     

Signaling mechanisms mediated by G-protein coupled receptors in human platelets

AIM: The present study deals with the investigation of mechanisms involved in the synergistic interaction between epinephrine and arachidonic acid (AA). METHODS: Venous blood was taken from healthy human volunteers reported to be free of medications for one week. Platelet aggregation was monitored at 37 ℃ using Dual-channel Lumi-aggregometer. The resulting aggregation was recorded for 5 min by the measurement of light transmission as a function of time. RESULTS: The data show that a synergism in platelet aggregation mediated by subthreshold concentrations of epinephrine (1 μmol/L) and AA (0.2 μmol/L) was inhibited by the α2-receptor antagonist(yohimbine, IC50=0.6 μmol/L) and an inhibitor of AA-cyclooxygenase (COX), indomethacin (IC50=0.25 μmol/L).In examining receptor influence on intraplatelet signalling pathways, it was found that the synergistic effect was inhibited by calcium channel blockers, verapamil (IC50=0.4 μmol/L) and diltiazem (IC5o=2.5 μmol/L), as well as by low concentrations of inhibitors of phospholipase C (PLC) (U73122; IC5o=0.2 μmol/L) and mitogens activated protein kinase (MAPK) (PD 98059; IC5o=3.8 μmol/L). Herbimycin A, a specific inhibitor of tyrosine light chain kinase (TLCK), showed inhibition at IC5o value of 15 μmol/L, whereas chelerythrine, a protein kinase C (PKC)inhibitor, had no effect up to 20 μmol/L. CONCLUSION: These data suggest that synergism between epinephrine and AA in platelet aggregation is triggered through receptors coupled to G-protein, which in turn, activate PLC,COX, and MAP kinase-signaling pathways.     

Dual effects of 5-hydroxytryptamine on stable analogue of thromboxane A~(2~_) induced aggregation and release reaction in rabbit platelets

目的：研究５ＨＴ对ＳＴＡ２血小板聚集和释放反应的影响及可能的分子机制．方法：以透光法，介质中ＡＴＰ含量及荧光图像法评价血小板变形，聚集反应和［Ｃａ２］ｉ水平．结果：（１）５ＨＴ预处理可消除ＳＴＡ２的血小板变形，ＳＴＡ２０３μｍｏｌ·Ｌ－１的聚集增强，ｌ－３μｍｏｌ·Ｌ－１的聚集不变，释放反应抑制．（２）５ＨＴ预处理增加ＳＴＡ２０３μｍｏｌ·Ｌ－１的［Ｃａ２＋］ｉ，降低３μｍｏｌ·Ｌ－１的［Ｃａ２＋］ｉ降低．（３）延长加入５ＨＴ和ＳＴＡ２的间隔，ＳＴＡ２０３μｍｏｌ·Ｌ－１的聚集增强，３μｍｏｌ·Ｌ－１的聚集不变，释放反应抑制．结论：５ＨＴ对ＳＴＡ２介导的聚集和释放反应有双重影响．对ＳＴＡ２［Ｃａ２＋］ｉ的调节可能是上述反应的分子机制．     

The influence of fenflumizole on platelet aggregation in patients with unstable angina pectoris

Summary We have studied the antiaggregatory effect of fenflumizole, a new non-steroidal antiinflammatory imidazole derivative, in ten patients with unstable angina pectoris.We have measured the aggregation induced by arachidonic acid (AA), ADP, and collagen, and serum or plasma concentrations of -thromboglobulin (-TG), platelet factor 4 (PF-4), thromboxane B₂ (TXB₂), and fenflumizole before, during, and after treatment with fenflumizole in two different regimens either as 10 mg b.i.d. for four days followed by 10 mg daily for six days (Group I,n=5), or as 20 mg b.i.d. for four days followed by 20 mg daily for six days (Group II,n=5).The threshold concentration of AA-induced platelet aggregation increased in both groups by the first day of treatment, the mean increase being significantly higher in Group II than in Group I. There was close correlation between serum fenflumizole and the threshold concentration of AA-induced platelet aggregation (r=0.95).A significant fall in TXB₂ occurred in both groups. In group I TXB₂ concentrations subsequently increased to initial values during treatment, whereas it remained significantly reduced in Group II. There were no significant changes in collagen and ADP aggregation, and -TG and PF-4 concentrations remained unchanged during and after the administration of fenflumizole.     

MN-9202对兔血小板聚集、5-HT释放、TXB_2合成及Ca~(2 )转运的影响(英文)

目的:研究新二氢吡啶类钙拮抗剂MN-9202对兔血小板激活的影响,并探讨其作用机制。方法:以Fu-ra-2 AM为荧光探针,采用时间扫描方式记录血小板内Ca~(2 )的变化;分别用HPLC/ECD和放射免疫测定法检测5-HT及TXB_2。结果:MN-9202剂量依赖地抑制ADP或凝血酶诱导的血小板聚集,抑制TXA_2的释放并且能有效阻滞激活血小板胞内Ca~(2 )水平的增加。MN-9202 1μmol·L~(-1)能抑制胶原15mg·L~(-1)诱导的5-HT释放反应,但对胶原45mg·L~(-1)诱导的反应无抑制作用。结论:MN-9202阻滞血小板Ca~(2 )内流并抑制血小板花生四烯酸代谢及激活反应。     

Involvement of cyclooxygenase, phospholipase C and MAP kinase pathways in human platelet aggregation mediated by the synergistic interaction of adrenaline and PAF

This study was conducted to examine the mechanism(s) of synergistic interaction of adrenaline and platelet-activating factor (PAF) mediated human platelet aggregation. We found that platelet aggregation mediated by subthreshold concentrations of PAF (5-8 nM) plus adrenaline (0.5-2 M) was inhibited by both ₂-adrenoceptor blocker (yohimbine) and PAF receptor antagonist (WEB2086). While examining the role of the downstream signalling pathways, we found that this synergism was inhibited by calcium channel blockers, verapamil, and diltiazem. In addition, platelet aggregation by co-addition of adrenaline and PAF was also inhibited by very low concentrations of phospholipase C (PLC) inhibitor (U73122; IC₅₀ = 0.2 _M), the MAP kinase inhibitor, PD98059 (IC₅₀ = 3 _M) and cyclooxygenase (COX-1) inhibitors including indomethacin (IC₅₀= 0.25 _M), flurbiprofen (IC₅₀ = 0.7 _M) and piroxicam (IC₅₀ = 7 _M). However, the COX-2 inhibitor, nimesulide, was also effective in inhibiting the aggregation. The inhibitors of tyrosine kinase (genistien) and phosphatidylinositol 3-kinase inhibitor (wortmannin) had no significant effects on platelet aggregation. These data suggest that the synergistic effect of adrenaline and PAF on human platelet aggregation is receptor-mediated and involves the activation of PLC/calcium, COX and MAP kinase signalling pathways.