银杏内酯B对大鼠脑缺血再灌注损伤的保护作用

目的探讨银杏内酯B对脑缺血再灌注损伤的保护作用及分子机制。方法大鼠随机分为假手术组、模型组、阳性药组(金纳多12 mg·kg-1)、银杏内酯B 1,2和4 mg·kg-1剂量组,采用线栓法建立大鼠大脑中动脉缺血再灌注模型,TTC染色测定梗死范围,HE染色检测脑组织病理变化,试剂盒检测大鼠脑组织匀浆中超氧化物歧化酶(SOD)活性、一氧化氮(NO)及丙二醛(MDA)含量的变化,透射电镜观察银杏内酯B对神经元超微结构改变,免疫组化法及Western blotting法检测胱天蛋白酶3,Bax和Bcl-2蛋白表达的影响,RT-CR检测胱天蛋白酶3、Bax和Bcl-2mRNA表达。结果与模型组比较,银杏内酯B可缩小梗死范围,减轻脑组织病理改变,明显提高脑组织SOD活性,降低脑组织中NO及MDA含量,免疫组化及Western blotting和RT-PCR结果显示脑缺血再灌注后胱天蛋白酶3、Bax蛋白及mRNA表达上调,Bcl-2表达降低;而银杏内酯B可下调胱天蛋白酶3、Bax的蛋白及mRNA表达,上调Bcl-2表达。结论银杏内酯B可减轻脑缺血再灌注神经细胞损伤,其机制可能与减少自由基产生,减轻NO神经毒性,抑制线粒体通路的诱导的神经细胞凋亡有关。     

七叶皂苷钠对沙土鼠脑缺血再灌注损伤ET和CGRP的影响

目的：观察七叶皂苷钠对沙土鼠脑缺血再灌注模型脑组织匀浆中内皮素（ ET）和降钙素基因相关肽（ CGRP）含量的影响。方法：采用结扎双侧颈总动脉缺血10 min再灌注2 h,建立沙土鼠脑缺血再灌注模型。七叶皂苷钠（10,20,40 mg·kg-1）术前3 d开始腹腔注射给药,qd,术后1 h给药1次。再灌注2 h后,放射免疫法测定脑组织ET和CGRP含量。结果：七叶皂苷钠各剂量组可降低脑组织ET水平至28.69~37.03 ng·L-1,与模型组比较有显著性差异（P〈0.05或0.01）,对脑组织CGRP水平则无明显影响（P〉0.05）。结论：七叶皂苷钠可能通过降低脑组织ET水平,实现对沙土鼠脑缺血再灌注损伤的保护作用。     

银杏内酯对实验性小动物脑缺血的保护作用

目的 :研究银杏内酯对实验性小动物脑缺血的保护作用。方法 :采用小鼠断头模型和大鼠急性不完全性脑缺血模型 ,测定小鼠断头后喘息时间和大鼠脑指数及脑含水量、脑毛细血管通透性以及血液流变学指标 ,观察银杏内酯对实验性脑缺血的保护作用。结果 :银杏内酯可延长小鼠断头后喘息时间 ;降低大鼠脑指数及脑含水量 ,抑制其脑毛细血管通透性升高 ,明显改善血液流变学指标 ,降低血液粘度。结论 :银杏内酯可预防实验性脑缺血损伤。     

银杏内酯保护大鼠肝脏缺血/再灌注损伤作用的机制探讨

目的：观察银杏内酯对大鼠肝脏缺血再灌注损伤的影响，探讨其保护大鼠肝缺血再灌注损伤作用的机制。方法：通过大鼠60min缺血、2h再灌注损伤模型，应用硝酸酶还原法测定肝脏缺血前5min和再灌注后10min，30min血清NO水平变化；测定再灌注后2h血清ALT、AST、LDH酶学差异和肝组织内ATP、MDA含量变化；再灌注2h取肝组织完成肝细胞、肝小叶显微结构和超微结构的观察。结果：肝脏缺血再灌注损伤后血清NO水平降低，ALT、AST、LDH水平升高；银杏内酯能提高再灌注后血清NO水平，并对ALT、AST、LDH的病理性升高有降低作用，且能改善肝脏缺血再灌注损伤的微循环，减轻肝细胞内超微结构的损害程度。结论：银杏内酯对大鼠肝脏缺血再灌注损伤有保护作用，其作用机制可能是通过NO介导的。     

银杏内酯对大鼠移植肝缺血再灌注损伤保护作用的研究

目的:观察银杏内酯对大鼠自体原位肝移植缺血再灌注损伤的影响,探讨其对大鼠移植肝缺血再灌注损伤的保护作用。方法:通过银杏内酯在门静脉-左肾静脉搭桥、肝后下腔静脉内置管分流法建立的大鼠自体原位肝移植模型上的应用,采用硝酸酶还原法测定肝脏缺血前和再灌注后5min、30min、2h血清血管活性递质一氧化氮(NO)和血浆内皮素(ET1)的水平变化;测定血清谷丙氨基转移酶(ALT)、谷草氨基转移酶(AST)、碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)的酶学差异和肝组织三磷酸腺苷(ATP)及丙二醛(MDA)的含量变化;再灌注2h取肝组织,用甲醛固定制成电镜标本,观察肝细胞、肝小叶超微结构。结果:银杏内酯能提高再灌注后血NO水平,并对ALT、AST、LDH的病理性升高有降低作用,且能改善肝脏缺血再灌注损伤的微循环,减轻肝细胞内超微结构的损害程度。结论:肝移植术前施行门腔分流是预防术后发生肝缺血再灌注损伤的有效措施;NO/ET1平衡可能是影响移植肝脏微循环血流量变化的调节因素。银杏内酯对大鼠肝缺血再灌注损伤有保护作用。     

银杏内酯对小鼠和大鼠脑缺血的保护作用

目的　研究银杏内酯 (TG)对小鼠密闭缺氧、急性脑缺血和大鼠局灶性脑缺血的保护作用。方法　采用小鼠密闭缺氧实验 ,观察TG对耗氧速度和存活时间的影响 ;结扎小鼠双侧颈总动脉及迷走神经造成脑缺血 ,观察TG对死亡率及死亡时间的影响 ;电凝大鼠一侧大脑中动脉造成局灶性脑缺血 (MCAO) ,观察TG对脑梗塞面积、行为及组织病理形态的影响。结果　TG(32mg·kg-1)降低脑缺血小鼠的死亡率 ,延长死亡时间 ;4,8,16mg·kg-1降低MCAO大鼠脑梗塞范围 ,改善行为障碍及脑组织病理形态。对密闭缺氧小鼠耗氧速度、存活时间无影响。结论　银杏内酯具有抗脑缺血作用     

银杏内酯B对缺血/再灌脑损伤大鼠的保护作用

目的探讨银杏内酯B对缺血/再灌注脑损伤大鼠的保护作用及其可能的作用机制。方法通过颈总动脉栓线造成大脑中动脉缺血,缺血3h后将线拔出以实现大脑中动脉血流再灌注,同时观察银杏内酯B对大鼠神经症状,脑梗死范围以及银杏内酯B对缺血侧脑组织匀浆SOD活力,MDA含量,LDH活力及LD含量的影响。并且进行了病理组织切片检查。结果银杏内酯B对缺血3h大鼠神经症状无影响,对再灌21h大鼠神经症状有明显的改善作用。银杏内酯B10、5mg·kg-1能明显降低脑梗死范围,同时银杏内酯B能升高SOD活力,减少MDA含量及LDH活力,但对LD含量无明显作用。病理切片检查结果表明,银杏内酯B能减轻缺血侧大脑的水肿及空泡现象。结论银杏内酯B对缺血/再灌注脑损伤有保护作用,该作用可能与其升高SOD活力,降低MDA含量及LDH活力有关。     

银杏内酯K对脑缺血的保护作用

目的 研究银杏内酯K对脑缺血的保护作用。 方法 采用小鼠常压耐缺氧实验,测定小鼠存活时间;小鼠双侧颈总动脉结扎引起急性不完全脑缺血模型,测定小鼠喘气时间、脑乳酸含量和碱性磷酸酶活性,观察组织形态学、脑指数和脑含水量的变化。 结果 银杏内酯K能剂量依赖性地延长小鼠缺氧缺血的存活时间;延长喘气时间,减少乳酸含量,降低碱性磷酸酶活性,减小脑指数和脑含水量。病理学组织检查显示,银杏内酯K能改善脑缺血再灌注造成的小鼠神经细胞的损伤,减少组织坏死。 结论 银杏内酯K对脑缺血有保护作用。     

银杏内酯对脑缺血再灌注大鼠线粒体ATP敏感性钾通道的影响

目的研究银杏内酯抗脑缺血再灌注损伤作用与线粒体ATP敏感性钾通道（mitoK-ATP）开放的关系。方法用Longa法制作大鼠局灶性脑缺血-再灌注损伤模型。造模前静脉给予银杏内酯15mg·kg^-1和（或）选择性mito K—ATP拮抗剂5羟基癸酸（5-HD）10mg·kg^-1预处理,以脑梗死体积、神经缺陷评分、SOD活性和丙二醛含量评价银杏叶提取物抗脑缺血再灌注损伤的作用与mitoKATP开放的关系。结果银杏内酯能够改善大鼠缺血一再灌注引起的脑功能和组织损伤,但此作用可被预先给予的5-HD减弱。结论银杏内酯抗脑缺血一再灌注损伤作用与mitoK-ATP开放有关。     

穿心莲内酯对大鼠脑缺血 再灌注损伤的影响

目的：观察穿心莲内酯(AP)对大鼠脑缺血 再灌注损伤的影响。方法：32只大鼠随机平分为AP高剂量组(2.50 mg·kg 1×2)、AP低剂量组(1.25 mg·kg 1×2)、模型组和对照组。结扎大鼠双侧颈总动脉，30 min后松开，再灌注60 min，复制脑缺血 再灌注损伤模型。AP高、低剂量组及模型组大鼠于颈总动脉结扎前10 min和剪断结扎线前(再灌注前)分别经颈静脉注入高、低剂量AP和等容积0.9%氯化钠注射液，再灌注维持60 min，对照组基本与模型组处理相同，但不结扎双侧颈总动脉。处死大鼠，测定再灌注后海马组织中过氧化物歧化酶(SOD)、Na＋ K＋ ATP酶、Ca2＋ ATP酶、谷胱甘肽过氧化物酶(GSH Px)活性及丙二醛(MDA)含量。结果：穿心莲内酯能明显提高脑缺血 再灌注后海马结构中SOD、GSH Px、Ca2＋ ATP酶、Na＋ K＋ ATP酶活性及降低脂质过氧化产物MAD含量。结论：穿心莲内酯对脑缺血 再灌注损伤的海马结构具有保护作用。     

高压氧对颅脑损伤鼠内皮素及降钙素基因相关肽的影响

目的观察高压氧(HBO)治疗急性颅脑损伤大鼠血浆和损伤皮层内皮素(ET)和降钙素基因相关肽(CGRP)含量的变化。方法32只SD大鼠,随机为分正常组,急性颅脑损伤组(分颅脑损伤后6、24、48h组),高压氧治疗组(分颅脑损伤后6、24、48h组),常氧高氮处理组(分颅脑损伤后6、24、48h组)。每组各8只大鼠。各组动物出舱后按时间要求尽量在安静状态下快速断头取血及损伤皮层,采用放免法测定血浆及损伤皮层ET及CGRP含量。结果SD大鼠急性颅脑损伤后,其血浆和损伤皮层组织ET含量有不同程度的升高,而CGRP含量有不同程度的降低;高压氧治疗后,各组血浆及损伤皮层组织ET含量均有不同程度地降低,而血浆及损伤皮层CGRP含量亦有不同程度升高。结论急性颅脑损伤的发生发展与血浆和损伤皮层组织ET含量升高和CGRP含量降低有关;高压氧治疗可能通过降低ET含量和升高CGRP含量,从而起到治疗急性颅脑损伤的作用     

前脑缺血及再灌流损伤后大脑皮层内皮素、降钙素基因相关肽和神经元凋亡的研究

目的：探讨大脑皮层缺血及再灌流内皮素（ET）,降钙素基因相关肽（CGRP）与神经元凋亡的变化规律及关系。方法：以前脑缺血及再灌流不同时段的大鼠为模型。用放免法检测皮层ET和CGRP含量;TUNEL法检测原位细胞凋亡。结果：缺血后15分。ET低于正常和假手术组：再灌流后进一步降低。12小时达最低水平,6天后恢复,缺血后CGRP升高,再灌流后继续升高,12小时和1天达高峰后下降,6天时恢复正常,缺血后神经元凋亡增加,再灌流后继续增加,1天时达高峰后缓慢下降,8天时基本恢复正常,ET量与凋亡细胞呈负相关,CGRP量与凋亡细胞呈正相关。结论：缺血和再灌流均可导致神经元凋亡,CGRP在缺血及再灌注早期升高,其对神经元凋亡可能具有双重作用。     

多沙唑嗪治疗轻中度高血压的疗效及其对血浆内皮素和降钙素基因相关肽的影响

目的观察多沙唑嗪治疗轻、中度原发性高血压的疗效,探讨多沙唑嗪对血浆内皮素(ET)和降钙素基因相关肽(CGRP)的影响。方法采用随机、对照、双盲法,将轻、中度原发性高血压48例分为两组各24例,治疗组和对照组分别给予多沙唑嗪和特拉唑嗪,均为2mg,po,qd,共治疗8周。结果治疗组和对照组降血压有效率分别为835%,783%,差异无显著性(P>005)。治疗组总胆固醇亦明显下降(P<005)。两组治疗后ET浓度下降、CGRP水平升高。结论多沙唑嗪为一安全有效的降血压药物,在降血压的同时有降血脂作用;多沙唑嗪的降血压作用可能部分与其拮抗ET、升高CGRP的浓度有关。     

Involvement of calcitonin gene-related peptide (CGRP) receptors in insulin-induced vasodilatation in mesenteric resistance blood vessels of rats

1. The vascular effect of insulin in the mesenteric resistance blood vessel and the role of calcitonin gene-related peptide (CGRP)-receptor in insulin-induced vascular responsiveness were investigated in rats.
2. The mesenteric vascular beds isolated from Wistar rats were perfused with Krebs solution, and perfusion pressure was measured with a pressure transducer. In preparations contracted by perfusion with Krebs solution containing methoxamine in the presence of guanethidine, the perfusion of insulin (from 0.1 to 3000 nM) caused a concentration-dependent decrease in perfusion pressure due to vasodilatation. The pD₂ value and maximum relaxation (%) were 6.94±0.22 and 43.9±5.2, respectively.
3. This vasodilator response to insulin was unaffected by 100 nM propranolol (β-adrenoceptor antagonist) plus 100 nM atropine (muscarinic cholinoceptor antagonist), 100 μM L-N^G-nitroarginine (nitric oxide synthase inhibitor), 1 μM ouabain (Na⁺-K⁺ ATPase inhibitor), or 1 μM glibenclamide (ATP sensitive K⁺-channel inhibitor).
4. In preparations without endothelium, perfusion of insulin produced a marked vasodilatation. The pD₂ value and maximum relaxation (%) were 7.62±0.21 and 81.0±4.6, respectively, significantly greater than in preparations with intact endothelium.
5. The vasodilator responses to insulin in the preparations without endothelium were significantly inhibited by CGRP[8–37], a CGRP receptor antagonist, whereas pretreatment with capsaisin, a toxin for CGRP-containing nerves, did not affect insulin-induced vasodilatation.
6. These results suggest that insulin induces non-adrenergic, non-cholinergic and endothelium-independent vasodilatation, which is partially mediated by CGRP receptors.

     

CGRP antagonists and antibodies for the treatment of migraine

Introduction: Migraine is a highly devastating neurovascular disorder that affects up to 16% of the population worldwide. In spite of intensive research, its origin remains enigmatic with no therapeutic option appropriate for all migraine patients. One of the leading hypotheses is related to the function of the calcitonin gene-related peptide (CGRP). Regardless, the pharmaceutical options currently applied for the acute and prophylactic treatment of migraine are not appropriate for all migraine patients.

Areas covered: This article is based on a literature review using the PubMed database and highlights the CGRP theory of the pathomechanism of migraine.

Expert opinion: Since migraine is a CGRP-related disorder, it appeared obvious to develop CGRP receptor antagonists that exert high efficacy, both intravenously and orally. Unfortunately, the frequent use of these antagonists results in an elevated liver transaminase level. In an attempt to bypass these harmful side effects, efforts should be made to modify these pharmacons. The use of fully humanized monoclonal antibodies (mAbs) that target CGRP and its receptors may also be possible. However, while Phase I and II clinical trials are promising, a long-term follow-up of these therapies is still needed.     

Homologous desensitization of calcitonin gene-related peptide-induced relaxation in rat intramural coronary arteries

We investigated the type of desensitization of calcitonin gene-related peptide (CGRP)-induced responses in rat isolated intramural coronary arteries using isometric myograph and FURA-2 technique. In coronary arteries precontracted with 9,11-dideoxy-11alpha,9alpha-epoxymethanoprostaglandin F2alpha (U46619), development of tachyphylaxis to CGRP is characterized by significant attenuation of CGRP-induced maximal reduction in the tension and [Ca2+](i) during the second CGRP concentration-response curve; however, there was no further reduction in the CGRP-induced maximum relaxation during the third CGRP concentration-response curve. There was no sign of tachyphylaxis to CGRP when CGRP concentration-response curves were recorded in 36 mM K+-depolarized coronary arteries contrary to the results obtained in 300 nM U46619-precontracted coronary arteries. Preincubation with colchicine did not prevent the development of tachyphylaxis to CGRP in U46619-precontracted coronary arteries, indicating no role for endocytosis. Development of tachyphylaxis to CGRP was completely abolished by preincubating the coronary arteries with 1 microM RO 31-8220, indicating a role for protein kinases. Pre-exposure of the coronary arteries to isoprenaline or forskolin did not attenuate the CGRP-induced relaxation in these vessels, indicating that the cAMP-protein kinase A (PKA) pathway is not involved. Like CGRP, the coronary arteries developed tachyphylaxis toward isoprenaline during the second exposure. However, there was no sign of tachyphylaxis to either forskolin or dibutyryl cAMP (dbcAMP) during the second exposure. In conclusion, these results suggest that development of tachyphylaxis to CGRP in U46619-precontracted coronary is related to CGRP receptor-mediated activation of protein kinase.     

Protection by capsaicin against attenuated endothelium-dependent vasorelaxation due to lysophosphatidylcholine

Previous studies have shown that pretreatment with calcitonin gene-related peptide (CGRP), a principal transmitter in sensory nerves, can protect the endothelial cell. We therefore evaluated whether in vivo capsaicin treatment prevents endothelial damage elicited by lysophosphatidylcholine (LPC) in the rat aorta. Acute treatment or repeated pretreatment with capsaicin resulted in stimulation of neurotransmitter release from sensory nerves or depletion of their transmitter content respectively. Vasodilator responses to acetylcholine (ACh) were examined in the aorta of these animals. Acute application of capsaicin (50 mg/kg) increased the plasma concentration of CGRP-like immunoreactivity (CGRP-LI) concomitantly with a reversal of the inhibition by LPC of endothelium-dependent ACh-induced relaxation in the isolated rat aorta. After repeated pretreatment with capsaicin to deplete sensory nerve neurotransmitter content the effects of capsaicin were absent as shown by the plasma CGRP-LI concentration and the vasodilator response to ACh. The results demonstrate that systemic capsaicin treatment, which evokes the release of CGRP from sensory nerves, protects the endothelial cell. The present study also suggests that CGRP may be an endogenous vascular protective substance. Received: 16 January 1997 / Accepted: 28 April 1997     

辣椒辣素对大鼠再灌注损伤的心肌早期和延迟保护作用(英文)

目的:研究辣椒辣素预处理的早期和延迟心肌保护。方法:采用Langendorff装置灌注离体心脏,记录心率、冠脉流量、左室内压以及最大变化速率,并测定降钙素基因相关肽(CGRP)的血浆浓度及灌注液中肌酸激酶(CK)的释放量。结果:辣椒辣素(50mg·kg~(-1),sc)改善心功能、降低CK释放,并升高CGRP的血浆浓度。预先用辣椒辣素耗竭感觉神经递质后,辣椒辣素的心肌保护和升高CGRP血浆浓度作用消失,应用辣椒辣素24h或48h后,其对缺血心肌仍具有保护作用。结论:辣椒辣素能诱导早期和延迟心肌保护,其保护作用可能与促进CGRP释放有关。     

经鼻靶向给予降钙素基因相关肽对蛛网膜下腔出血后海马区细胞凋亡的影响

目的 探讨经鼻靶向中枢给予降钙素基因相关肽（calcitonin gene-related peptide,CGRP）对海马细胞凋亡和脑损伤的作用。方法 枕大池2次注血法制作蛛网膜下腔出血（subarach-noid hemorrhage,SAH）模型。将48只♂ Wistar大鼠随机分为正常对照组、SAH组、生理盐水（NS）+SAH组（经鼻给予NS）、CGRP+SAH组（经鼻给予CGRP）,每组12只。于第2次注血3 d后,采用免疫荧光技术检测海马组织中bcl-2和caspase-3的蛋白表达。结果 免疫荧光染色显示bcl-2和caspase-3在正常对照组大鼠海马组织中只观察到极少量表达;SAH组、NS+SAH组bcl-2和caspase-3蛋白表达明显增多;与SAH组和NS+SAH组相比较,经鼻给予CGRP治疗后,bcl-2表达显著升高,caspase-3表达水平显著降低,差异均具有统计学意义（P<0.01）。结论 CGRP经鼻靶向中枢给药能有效抑制SAH大鼠海马组织细胞凋亡,对脑损伤具有显著保护作用。     

降钙素基因相关肽抑制内皮素促血管平滑肌细胞增殖作用

本工作应用培养的自发性高血压大鼠主动脉平滑肌细胞.通过~3H-胸腺嘧啶核苷及~3H-亮氨酸参入的方法,观察到降钙素基因相关肽明显抑制培养的血管平滑肌细胞的增殖和内皮素促血管平滑肌细胞增值作用.提示降钙素基因相关肽可能是机体天然存在的内皮素拮抗剂。