异丙酚促进大鼠脑缺血/再灌注中CGRP释放的机制研究

【目的】探讨异丙酚在大鼠脑缺血/再灌注(IR)损伤中是否促进内源性保护物质降钙素基因相关肽(CGRP)的释放及其调节机制。【方法】实验大鼠分为对照组、假手术组、脑IR组及脑IR 异丙酚治疗组,测定CO、放射免疫测定大鼠脑组织中CGRP、cGMP含量,免疫组化测定HO-1的表达。【结果】脑IR期间,脑IR 异丙酚治疗组的HO-1、CO、cGMP和CGRP显著高于脑IR组和假手术组(P<0.05),且HO-1与CO、CO与cGMP、cGMP与CGRP的表达变化呈正相关(P<0.05),假手术组和对照组间相比较差异无显著性。【结论】异丙酚能促进IR期间CGRP的升高,对大鼠脑IR损伤具有明显的保护作用,作用机制之一可能是通过HO-1-CO-cGMP途径促进CGRP的合成和释放,减轻缺血再灌注的损伤反应。     

吗啡对急性心肌梗死再灌注损伤保护效应的实验研究

目的　通过测定急性心肌梗死再灌注损伤模型大鼠的血浆降钙素基因相关肽 (CGRP)、内皮素(ET 1)浓度及心肌梗死面积的变化 ,探索吗啡对急性心肌损伤的保护机制。方法　将 4 0只 SD大鼠随机分为单纯缺血再灌注模型组、吗啡预处理组、吗啡 纳洛酮组和手术对照组 ,每组各 10只。采用戊巴比妥钠(40 m g/ kg)腹腔注射麻醉大鼠 ,采用穿线结扎左冠状动脉前降支制备大鼠心肌缺血再灌注模型。用放射免疫法测定血浆 CGRP和 ET 1浓度 ,同时测定血清中肌酸磷酸激酶同工酶 (CK MB)含量 ;用氯化三苯四唑(TTC)法染色和数码照相计算机图像分析系统计算心肌梗死面积。结果　大鼠左冠状动脉前降支结扎 10 m in时血浆 ET 1和 CGRP浓度较手术对照组显著增高 (P均 <0 .0 1) ;再灌注 4 .5 h时吗啡预处理组血浆 ET 1及 CK MB浓度较结扎 10 m in时显著降低 ,心肌梗死面积也显著缩小 (P均 <0 .0 1) ;而血浆 CGRP浓度则显著增高 (P<0 .0 1) ;吗啡预处理组以上变化较吗啡 纳洛酮组差异有统计学意义 (P均 <0 .0 1)。结论　吗啡预处理可通过显著降低 ET 1而增加 CGRP血浆浓度、缩小心肌梗死面积 ,对急性心肌梗死后再灌注心肌产生保护效应。     

腰椎间盘突出症患者血浆CGRP升高的机制探讨

[目的]探讨腰椎间盘突出症患者血浆降钙素基因相关肤(CGRP)水平及其调节机制.[方法]实验分为对照组、腰椎间盘突出症患者组,免疫化学法、RT-PCR法测定患者血浆血红素氧合酶-1(HO-1)、一氧化碳(CO)、环磷酸乌苷(cGMP)、CGRP的表达量.[结果]腰椎间盘突出症患者血浆的HO-1、CO、cGMP和CGRP显著高于对照组(P<0.05),且HO-1与CO、CO与cGMP、cGMP与CGRP的表达变化呈正相关(P<0.05).[结论]腰椎问盘突出症患者血浆CGRP升高,通过HO-1-CO-cGMP途径促进CGRP的合成和释放可能是其血浆CGRP升高的调节机制之一.     

皮层扩布性抑制对血浆降钙素基因相关肽与P物质的影响

目的:建立偏头痛大鼠皮层扩布性抑制(cortical spreading depression,CSD)模型,研究CSD对大鼠血浆降钙素基因肽(calcitonin gene-related peptide,CGRP)和P物质(substance P,SP)的影响。方法:大鼠随机分为CSD组(n=10)、对照组(n=10),分别用氯化钾溶液及生理盐水浸润滤纸片刺激枕叶皮层,在额叶皮层记录CSD波,利用放射免疫技术测定大鼠血浆中的CGRP、SP水平,进行成组t检验比较。结果:CSD组大鼠记录到CSD波,对照组大鼠未记录到CSD波;CSD组大鼠血浆CGRP、SP水平高于对照组(P<0.05)。结论:利用氯化钾溶液浸润滤纸片刺激大鼠枕叶皮层成功建立了CSD模型,CSD使血浆CGRP、SP水平增加,说明CSD可能通过一定的机制激活了三叉神经血管反射,进而导致偏头痛的发生。     

玉竹提取物A对小鼠单核细胞体外诱生血栓素B2分泌量的影响

目的观察小鼠单核细胞在体外经内毒素刺激分泌血栓素B2的情况,及不同浓度玉竹提取物A对其分泌量的影响。方法实验于2004-06/2004-08在锦州医学院免疫实验室进行。选择普通级健康雄性昆明小鼠36只,随机分为正常对照组、模型对照组、玉竹提取物A500m g/L组、玉竹提取物A1000m g/L组、玉竹提取物A1500m g/L组,玉竹提取物A2000m g/L组共6组,每组6只。36只小鼠摘眼球取血,分离外周血单核细胞,分置24孔培养板中,每孔0.5m L。每组设6个平行孔,大肠杆菌内毒素为终浓度。正常对照组每孔加完全16400.5m L;模型对照组同样每孔加完全16400.5m L;同时4个实验组的单核细胞内分别加入相应浓度的玉竹提取物A;另取两个24孔培养板,每孔只加单核细胞悬液1m L。上述分离之单核细胞培养3d后换液1次,除正常对照组外,将10m g/L的大肠杆菌内毒素10μL加入其余5组,共育2h;同时取只加单核细胞悬液的后两板,每组加大肠杆菌内毒素浓度分别为0.01,0.1,1,10,100,400mg/L,各10μL,共育2h。然后收集每孔上清液,放免分析法测定上清液中血栓素B2含量。观察体外给予不同浓度大肠杆菌内毒素,对血栓素B2分泌量的影响;不同浓度玉竹提取物A对同一浓度大肠杆菌内毒素刺激的血栓素B2分泌量的影响。结果36只小鼠均进入结果分析。①大肠杆菌内毒素维持在0.01,0.1,1,10mg/L时,其刺激小鼠外周血单核细胞合成血栓素B2水平呈剂量依赖关系,即随大肠杆菌内毒素浓度增加,血栓素B2合成水平亦升高(800,950,1180,1500ng/L),大肠杆菌内毒素为10m g/L时,刺激血栓素B2合成速率达峰值;当内毒素刺激量增至100,400m g/L时,血栓素B2合成水平不再升高,而呈下降趋势(1100,900ng/L)。②当用10m g/L的大肠杆菌内毒素分别刺激除正常对照组外的其余5组的单核细胞时,模型对照组血栓素B2分泌量明显高于正常对照组[(1382±98),(823±78)ng/L,t=10.93,P<0.01],4个浓度(500,1000,2000,4000m g/L)玉竹提取物A组血栓素B2的量明显低于模型对照组[(805±75),(812±77),(817±81),(783±70),(1382±98)ng/L,t=11.45,11.20,10.88,12.18,P<0.01],与正常对照组(823±78)ng/L无显著差异。结论内毒素体外可以刺激单核细胞分泌血栓素B2,且刺激量为10mg/L时,单核细胞合成血栓素B2最旺盛;不同浓度玉竹提取物A体外均可显著抑制血栓素B2的分泌,但随着药物浓度的增大,其抑制作用并未增强。     

尼莫地平对大鼠烫伤后库普弗细胞白介素-1β和白介素-6产生的抑制作用

目的 :探讨钙离子通道阻断剂尼莫地平对烧伤后库普弗细胞 (KC)合成释放白介素 1β(IL 1β)、IL 6的调控作用 ,为寻找一种有效减轻、控制烧伤后过度全身炎症反应的措施提供理论依据。方法 :内灌注消化、密度梯度离心法分离培养正常 SD大鼠 KC,显微荧光分光光度计复合倒置显微镜技术观察烫伤血清作用下单个 KC细胞内钙 (〔 Ca2 +〕i)变化 ,酶联免疫吸附法 (EL ISA)测定烫伤血清培养的 KC上清中 IL 1β和IL 6的浓度变化。 SD大鼠行 30 %总体表面积 (TBSA) 度烫伤 ,伤后 6 h分离 KC,RNA酶保护分析法测定KC中两种细胞因子 m RNA的表达量 ,并测定血浆细胞因子水平 ;观察尼莫地平存在时上述结果的改变。结果 :与对照组相比 ,烧伤组 KC〔 Ca2 + 〕i峰值及培养上清中 IL 1β、IL 6浓度增加值均显著增加 (P均 <0 .0 1) ,在 1μm ol/L尼莫地平存在时 ,两者均显著减少 (P均 <0 .0 1)。烧伤后 6 h KC中 IL 1β和 IL 6的m RNA表达量及其血浆水平均显著升高 ,静脉予尼莫地平 (40 μg· kg- 1 · h- 1 )后两者均显著减少 (P均 <0 .0 1)。结论 :大鼠严重烧伤后 ,KC合成释放 IL 1β和 IL 6 ,此过程通过细胞内钙离子通道信号传导途径实现。尼莫地平能抑制烧伤后 KC中 IL 1β和 IL 6 m RNA表达 ,使 KC产生 IL 1β、IL 6明显     

硝酸酯类药物对慢性缺氧大鼠肺循环的影响

目的：探讨缺氧性肺动脉高压(HPH)的形成机制及硝酸酯类药物降低肺动脉压的作用机理。方法：建立慢性缺氧大鼠模型，测定慢性缺氧时及消心痛治疗后的平均肺动脉压(mPAP)、血浆内皮素-1(ET-1)及血清一氧化氮(NO)水平。结果：慢性缺氧可导致大鼠mPAP增高，同时血浆ET-1产生增多和NO合成减少；消心痛可明显抑制缺氧所致的ET-1释放，并使血清NO水平显著提高，从而明显降低大鼠mPAP。结论：缺氧性肺动脉高压的形成与缺氧时血中ET-1及NO水平变化有关；而消心痛可能通过抑制ET-1的释放及提供外源性NO或促进内源性NO合成而起到降低肺动脉压的作用。     

LRG在脂多糖预处理诱导大鼠脑保护效应中的作用研究

目的:通过测定不同组大鼠脑缺血/再灌注损伤模型中脂多糖应答基因分子(Iipopolysaccharide response gene,LRG)表达水平的变化与血浆降钙素基因相关肽(CGRP)、内皮素(ET-1)、肿瘤坏死因子-α(TNF-α)含量及大鼠神经功能评分和脑梗死容积之间的关系,探索脂多糖(Iipopolysaccharide,LPS)预处理诱导脑保护效应的核心分子机制.方法:将SD大鼠随机分为假手术组、缺血对照组和脂多糖预处理组.采用戊巴比妥钠(40 mg/kg)腹腔注射麻醉大鼠,采用大脑中动脉栓塞模型制备大鼠脑缺血/再灌注模型.免疫印迹法结合图像分析软件半定量计算LRG分子表达水平的变化,放射免疫法测定血浆CGRP、ET-1和TNF-α浓度,采用gareia评分法进行神经功能评分,用氯化三苯四唑(TTC)染色法和计算机图像分析系统计算脑梗死容积.结果:相比于缺血对照组,脂多糖预处理组大鼠脑缺血/再灌注后72 h LRG表达水平明显上调,血浆CGRP浓度显著增高,而血浆ET-1和血清TNF-α浓度则显著降低,同时,脂多糖预处理组大鼠神经功能评分较缺血对照组明显改善,脑梗死容积也显著缩小.结论:脂多糖预处理可诱导LRG分子表达水平上调,显著降低ET-1、TNF-α而增加CGRP浓度,从而对急性脑缺血再灌注损伤产生一定的保护效应.     

抗生素的应用与失血性休克肠源性释放的关系

目的:探讨失血性休克时使用抗生素是否会增加肠源性内毒素释放及其意义。方法:制作大鼠失血性休克模型,分别通过静脉注射给予罗氏芬、环丙沙星及庆大霉素,休克复苏后6h活杀动物,取门静脉血,动态观察门静脉血浆中内毒素的变化。结果:大鼠失血性休克后,对照组、庆大霉素组和环丙沙星组门静脉血内毒素水平明显升高,后两组内毒素水平高于对照组(P<0.01),两组间差异无显著性(P>0.05);罗氏芬组内毒素低于庆大霉素组、环丙沙星组和对照组(P<0.01)。结果:应激状态下不同抗生素的使用导致了不同的内毒素释放水平,合理选择抗生素,减少内毒素释放对临床具有重要意义。     

全身炎症反应综合征患者血浆乳酸水平与炎症反应的相关性研究

目的研究全身炎症反应综合征(SIRS)患者急性期反应以及血浆乳酸水平与炎症反应标志物C-反应蛋白(CRP)、内毒素浓度的相关性。方法符合SIRS诊断32例于入院时、入院后第2和5天早晨空腹抽取肘静脉血8ml,应用氧化酶法在日立全自动生化分析仪上进行测定血浆乳酸,速率散射免疫比浊法测定CRP和基质偶氮显色鲎试验测定法测定内毒素浓度,并设健康对照组。结果血浆乳酸水平、CRP水平和内毒素浓度在时相监测点均同步升高,与对照组比较差异有统计学意义(P均0.01);血浆乳酸水平与CRP浓度、内毒素含量呈正相关(P0.01);器官功能不全组患者血浆乳酸水平、CRP水平和内毒素浓度高于器官功能正常组患者(P0.05)。结论 SIRS患者炎症急性期反应时,具有直接或间接作用使血浆乳酸水平增高,同时乳酸水平增高也有可能加重炎症反应。因此,监测SIRS患者血浆乳酸水平,能反映炎症反应的程度,是判断治疗效果和预后的有效措施。     

严重烧伤休克期心脏调节肽变化的研究

目的探讨严重烧伤休克期血浆降钙素基因相关肽(CGRP)和神经肽Y(NPY)变化及其意义。方法采用放射免疫法(RA)测定60例严重烧伤患者休克期不同时相点血浆CGRP、NPY含量。结果严重烧伤休克期后3 h血浆CGRP降低,12 h达最低值,伤后48 h仍低于正常对照组(P<0.05);血浆NPY于伤后1 h升高,12 h达峰值,48 h仍高于正常对照组(P<0.05),血浆CGRP与NPY呈显著负相关(P<0.01)。结论血浆CGRP降低、NPY升高在严重烧伤休克期中起着重要作用,可能参与和促进了烧伤休克发生和发展。     

Effects of propofol on hemodynamic and inflammatory responses to endotoxemia in rats

OBJECTIVE: To document the effects of propofol on the hemodynamic and inflammatory responses to endotoxemia in an animal model. DESIGN: Randomized, prospective laboratory study. SETTING: University experimental laboratory. SUBJECTS: Thirty-two male rats. INTERVENTIONS: The animals were randomly assigned to one of four groups: a) endotoxemia group (n = 8), which received intravenous Escherichia coli endotoxin (15 mg/kg over 2 mins); b) control group (n = 8), which was treated identically to the endotoxemia group except for the substitution of 0.9% saline for endotoxin; c) propofol group (n = 8), which was treated identically to the control group but also received propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after the injection of 0.9% saline; and d) propofol-endotoxemia group (n = 8), which was treated identically to the endotoxemia group with the additional administration of propofol (10 mg/kg bolus, followed by infusion at 10 mg/kg/hr) immediately after endotoxin injection. MEASUREMENTS AND MAIN RESULTS: Hemodynamics, arterial blood gases, and acid-base status were recorded and the blood propofol concentrations and plasma cytokine concentrations were measured during the 5-hr observation. Microscopic findings of lung tissue for each group were obtained at necropsy. The systolic arterial pressure and heart rate of the propofol-endotoxemia group were similar to those of the endotoxemia group. The increases in the plasma cytokine (tumor necrosis factor, interleukin-6, and interleukin-10) concentrations, in the base deficit, and in the infiltration of neutrophils in the air space or vessel walls of the lungs were attenuated in the propofol-endotoxemia group compared with the endotoxemia group. CONCLUSIONS: Propofol attenuated cytokine responses, base deficit, and activation of neutrophils to endotoxemia. These findings suggest that propofol may inhibit inflammatory response and prevent the development of metabolic acidosis during endotoxemia.     

Inhibition of adenosine deaminase attenuates endotoxin-induced release of cytokines in vivo in rats.

The purpose of this study was to investigate in vivo the effects of modulating the adenosine system on endotoxin-induced release of cytokines and changes in heart performance and neurohumoral status in early, profound endotoxemia in rats. Time/pressure variables of heart performance and blood pressure were recorded continuously, and plasma levels of tumor necrosis factor alpha (TNFalpha), interleukin 1-beta (IL-1beta), plasma renin activity (PRA), and catecholamines were determined before and 90 min after administration of endotoxin (30 mg/kg of lipopolysaccharide, i.v.). Erythro-9[2-hydroxyl-3-nonyl] adenine (EHNA; an adenosine deaminase inhibitor) had no effects on measured time-pressure variables of heart performance under baseline conditions and during endotoxemia, yet significantly attenuated endotoxin-induced release of cytokines and PRA. Pretreatment with the non-selective adenosine receptor antagonist DPSPX not only prevented the effects of EHNA but also increased the basal release of cytokines and augmented PRA. At baseline, caffeine (a non-selective adenosine receptor antagonist) increased HR, +dP/dtmax, heart rate x ventricular pressure product (HR x VPSP) and +dP/dtmax normalized by pressure (+dP/dtmax/VPSP), and these changes persisted during endotoxemia. Caffeine attenuated endotoxin-induced release of cytokines and augmented endotoxin-induced increases in plasma catecholamines and PRA. Pretreatment with propranolol abolished the effects of caffeine on heart performance and neurohumoral activation during the early phase of endotoxemia. 6N-cyclopentyladenosine (CPA; selective A1 adenosine receptor agonist) induced bradicardia and negative inotropic effects, reduced work load (i.e., decreased HR, VPSP, +dP/dtmax, +dP/dtmax/VPSP and HR x VPSP) and inhibited endotoxin-induced tachycardia and renin release. CGS 21680 (selective A2A adenosine receptor agonist) decreased blood pressure under basal condition but did not potentiate decreases in blood pressure during endotoxemia. CGS 21680 completely inhibited endotoxin-induced release of TNFalpha, augmented sympathetic activity and PRA, and increased +dP/dtmax and +dP/dtmax/VPSP in the absence and presence of endotoxin. The present study provides strong evidence that inhibition of adenosine deaminase reduces cytokine release in vivo without producing significant hemodynamic and cardiac effects during the early phase of profound endotoxemia in rats. The augmented neurohumoral activation induced by caffeine is associated with decreased cytokine release induced by endotoxin. Further studies are warranted to determine the impact of these effects on cardiac function and hemodynamics in the late phase of endotoxemia.     

Sumatriptan causes parallel decrease in plasma calcitonin gene-related peptide (CGRP) concentration and migraine headache during nitroglycerin induced migraine attack

Sumatriptan-induced changes in plasma calcitonin gene-related peptide (CGRP) concentration and headache intensity were investigated in 19 female migraineurs during nitroglycerin-induced migraine attack. Sumatriptan nasal spray was administered 120 min after the onset of the attack. Blood samples were obtained immediately before and 60 min after sumatriptan administration. In those subjects whose migraine attack improved considerably 60 min after the treatment the plasma CGRP concentration decreased significantly (P<0.05). In contrast, plasma CGRP concentration failed to change in patients whose headache did not improve. In addition, plasma CGRP concentrations showed significant positive correlations with the headache scores both 60 and 120 min after sumatriptan administration (P<0.05). According to our results plasma CGRP concentration decreases parallel to headache intensity during sumatriptan treatment and this decrease in CGRP predicts effectiveness of antimigraine drug therapy. This supports that one of the main effects of triptans is to decrease CGRP release.     

Effects of endotoxemia on cyclic nucleotides in the unanesthetized sheep

The effects of endotoxemia on hemodynamics, pulmonary fluid, and solute exchange and cGMP and cAMP concentrations in lung lymph and pulmonary artery and left atrial blood were studied in six unanesthetized sheep. Cyclic AMP levels increased early in the endotoxin reaction, reaching peak concentration 1 hr after endotoxemia (during the period of pulmonary hypertension). Cyclic GMP levels increased gradually during the endotoxin reaction, reaching peak concentrations 5 hr after endotoxemia (during the period of "increased pulmonary vascular permeability"). The changes observed in cyclic nucleotide levels in lung lymph and pulmonary artery and left atrial blood suggested pulmonary production of cGMP but not cAMP. Cyclic AMP concentrations correlated with PPA, Qlymph, and a drop in the L/P ratio, whereas lung lymph cGMP correlated with an increased clearance of protein in the lymph. These results further characterize the sheep endotoxin reaction and suggest a possible role for cyclic nucleotides in the pathogenesis of the changes in lung vascular function that follow endotoxin infusion in sheep.     

偏头痛患者头痛缓解初期血中CGRP与SP含量观察

目的：观察偏头痛患者头痛缓解初期血中降钙素基因相关肽（ＣＧＲＰ）与Ｐ物质（ＳＰ）含量的变化。方法：采用放射免疫的方法,对４９例头痛缓解初期无先兆偏头痛患者及２８例健康人血浆中ＣＧＲＰ与ＳＰ的含量进行了测定。结果：与正常对照组相比,偏头痛组的ＣＧＲＰ与ＳＰ含量降低,差异有显著性意义,其中以“尚余头部不适”组的降低尤为明显。结论：偏头痛的发病可能与感觉神经系统释放的ＣＧＲＰ和ＳＰ变化有关。     

Effects of sumatriptan on capsaicin-induced carotid haemodynamic changes and CGRP release in anaesthetized pigs

It is suggested that during a migraine attack capsaicin-sensitive trigeminal sensory nerves release calcitonin gene related peptide (CGRP), resulting in cranial vasodilatation and central nociception. Hence, inhibition of trigeminal CGRP release may prevent the above vasodilatation and, accordingly, abort migraine headache. Therefore, this study investigated the effects of sumatriptan (100 and 300 microg/kg, i.v.) on capsaicin-induced carotid haemodynamic changes and on CGRP release. Intracarotid (i.c.) infusions of capsaicin (10 microg/kg/min, i.c.) increased total carotid, arteriovenous anastomotic and capillary conductances as well as carotid pulsations, but decreased the difference between arterial and jugular venous oxygen saturations. Except for some attenuation of arteriovenous anastomotic changes, the capsaicin-induced responses were not affected by sumatriptan. Moreover, i.c. infusions of capsaicin (0.3, 1, 3 and 10 microg/kg/min, i.c.) dose-dependently increased the jugular venous plasma concentrations of CGRP, which also remained unaffected by sumatriptan. The above results support the contention that the therapeutic action of sumatriptan is mainly due to cranial vasoconstriction rather than trigeminal (CGRP release) inhibition.     

NO-induced migraine attack: strong increase in plasma calcitonin gene-related peptide (CGRP) concentration and negative correlation with platelet serotonin release

The aim of the present study was to investigate changes in the plasma calcitonin gene-related peptide (CGRP) concentration and platelet serotonin (5-hydroxytriptamine, 5-HT) content during the immediate headache and the delayed genuine migraine attack provoked by nitroglycerin. Fifteen female migraineurs (without aura) and eight controls participated in the study. Sublingual nitroglycerin (0.5 mg) was administered. Blood was collected from the antecubital vein four times: 60 min before and after the nitroglycerin application, and 60 and 120 min after the beginning of the migraine attack (mean 344 and 404 min; 12 subjects). In those subjects who had no migraine attack (11 subjects) a similar time schedule was used. Plasma CGRP concentration increased significantly (P<0.01) during the migraine attack and returned to baseline after the cessation of the migraine. In addition, both change and peak, showed significant positive correlations with migraine headache intensity (P<0.001). However, plasma CGRP concentrations failed to change during immediate headache and in the subjects with no migraine attack. Basal CGRP concentration was significantly higher and platelet 5-HT content tended to be lower in subjects who experienced a migraine attack. Platelet serotonin content decreased significantly (P<0.01) after nitroglycerin in subjects with no migraine attack but no consistent change was observed in patients with migraine attack. In conclusion, the fact that plasma CGRP concentration correlates with the timing and severity of a migraine headache suggests a direct relationship between CGRP and migraine. In contrast, serotonin release from platelets does not provoke migraine, it may even counteract the headache and the concomitant CGRP release in this model.