Protection of ischemic preconditioning mediated by endogenous opioid peptides in rat hindquarters

研究了内源性阿片肽介导大鼠后肢缺血预适应的保护作用．后肢缺血２ｈ，乙酰胆碱（ＡＣｈ）诱导的血管内皮依赖性舒张性反应明显下降．缺血预适应（缺血５ｍｉｎ，再灌５ｍｉｎ，重复３次）能显著减弱长时间缺血对ＡＣｈ舒血管效应的抑制作用，这种保护作用可被纳洛酮（３ｍｇ·ｋｇ－１）取消．预先给予吗啡（３００μｇ·ｋｇ－１）也能产生与缺血预适应相同的血管内皮保护作用．然而，预先用辣椒素（５０ｍｇ·ｋｇ－１）耗竭降钙素基因相关肽后，吗啡的保护作用被取消．结果提示，内源性阿片肽介导大鼠后肢缺血预适应的血管保护作用，其机理可能涉及内源性降钙素基因相关肽．     

Mediation of calcitonin gene-related peptide in protection of ischemic preconditioning in rat hindlimbs

目的：研究降钙素基因相关肽（ＣＧＲＰ）介导缺血预适应对血管内皮的保护．方法：大鼠后肢缺血２ｈ后，观察乙酰胆碱诱导血管内皮依赖性舒张反应．结果：缺血不影响去甲肾上腺素的缩血管效应，但能显著削弱乙酰胆碱的舒血管效应．缺血预适应能阻止长时间缺血对乙酰胆碱舒血管效应的抑制作用，这种保护作用可被反复应用辣椒素耗竭ＣＧＲＰ所取消．急性应用辣椒素促进ＣＧＲＰ释放或外源性应用ＣＧＲＰ均可产生预适应样的保护作用．结论：大鼠后肢缺血预适应对内皮细胞的保护与辣椒素敏感的感觉神经有关；ＣＧＲＰ能模拟缺血预适应保护血管．     

降钙素基因相关肽介导大鼠后肢缺血预适应的保护作用

目的：研究降钙素基因相关肽（ＣＧＲＰ）介导缺血预适应对血管内皮的保护。方法：大鼠后肢缺血２ｈ后，观察乙酰胆碱诱导血管内皮依赖性舒张反应。结果：缺血不影去甲蛹 腺素的缩血管效应，但能显著削弱乙酰胆碱的舒血管效应。缺血预适应能阻止长时间缺血对惭酰胆碱舒血管效应的抑制作用，这种保护作用可被反复应用辣椒素耗竭ＣＧＲＰ所取消。急性应用辣椒素促进ＣＧＲＰ释放或外源性应用ＣＧＲＰ均可产生预适应样的保护作用。结论     

缺血预适应心肌保护作用的神经递质调节

缺血预适应是指心脏遭受短暂缺血后能耐受随后较长时间缺血损伤,是近年发现的一种预防心肌缺血损伤的有效措施。缺血预适应的心肌保护作用是心脏释放内源性心血管活性物质所介导。神经递质（儿茶酚胺、乙酸胆碱、降钙素基因相关肽、阿片肽等）可能是介导缺血预适应的内源性心肌保护物质。外源性应用神经递质能模拟缺血预适应的心肌保护作用。神经递质可同其它内源性活性物质相互作用。神经递质介导缺血预适应可能是通过与其相应受体结合,触发细胞内信息转导途径,激活蛋白激酶C产生心肌保护作用。     

1,6-二磷酸果糖镁对异丙肾上腺素所致大鼠心肌损伤的保护作用

研究1,6-二磷酸果糖镁（FDP-Mg）对异丙肾上腺素（Iso）所致心肌损伤的保护作用. 大鼠sc Iso (8 mg·kg^-1·d^-1, 3 d)造成心肌损伤模型,测定心肌组织和血清肌酸激酶（CK）, 乳酸脱氢酶（LDH）, 超氧化物歧化酶（SOD）活性及丙二醛（MDA）, Mg²⁺, P和K⁺含量. 结果：每天给予Iso的同时给予FDP-Mg（250-1000 mg·kg^-1·d^-1, 3 d）能明显降低血清CK,LDH水平,抑制心肌组织中CK,LDH释放,提高血清和心肌SOD活性,降低MDA水平,提高心肌及血清Mg²⁺和P含量,降低血清K⁺浓度。综合了FDP-Na₂（530 mg·kg^-1·d^-1, 3 d）和硫酸镁（150 mg·kg^-1·d^-1, 3 d）的作用特点。结果表明,FDP-Mg对Iso所致大鼠心肌损伤具有保护作用,与其抗氧化及改善心肌代谢有关.     

速激肽受体拮抗剂对白三烯C4诱导豚鼠气道收缩和微血管渗漏的作用

本实验探讨了内源性速激肽是否参与白三烯C₄(LTC₄)的气道效应. LTC₄(0.5 μg·kg^-1, iv)可增高豚鼠肺内压(IPP)和气道内依文思蓝渗出。速激肽NK-1受体拮抗剂CP-96345｛(2S, 3S)-顺式-2-( 二苯甲基)-N-［(2-甲氧苯)-甲基］-1-杂氮双环［2.2.2］辛烷-3-胺｝ 1 mg·kg^-1，iv，可减弱LTC₄诱导的依文思蓝渗出；NK-2受体拮抗剂SR-48968｛(S)-N-甲基-N-［4-(4-乙酰氨基-4-苯基哌啶)-2-(3,4-二氯苯基)丁基］苯甲酰胺｝，1 mg·kg^-1， iv，可抑制IPP的增高. 白三烯拮抗剂ONO-1078 (0.03 mg·kg^-1, iv)可阻断这两种反应. 结果说明内源性速激肽增强 LTC₄的气道作用，其中NK-1受体介导微血管渗漏，NK-2受体介导支气管收缩.     

黄芪提取物对大鼠局灶性脑缺血再灌注血脑屏障损伤的影响

目的 研究黄芪提取物(extract of astragalus,EA)对大鼠局灶性脑缺血(MCAO)再灌注的血脑屏障损伤的影响。方法 采用线栓法制备MCAO再灌注模型,观察EA对缺血再灌注大鼠的神经功能障碍、脑梗死体积和脑含水量、外周血循环内皮细胞(CEC)含量、缺血脑组织中细胞间粘附分子(ICAM-1)的表达、缺血侧脑组织皮质血脑屏障超微结构的病理学变化的影响。结果 EA80 mg·kg^-1,EA(40,80 mg·kg^-1)、EA(20,40,80 mg·kg^-1)可分别改善缺血再灌注2,8,24 h大鼠的神经功能障碍;能明显降低外周血中的CEC含量,明显减轻缺血脑组织的脑水肿和脑梗死体积,对脑缺血再灌注后血脑屏障超微结构的病理改变有一定的改善作用;能减少ICAM-1免疫反应阳性血管数。结论 EA对局灶性脑缺血再灌注损伤大鼠有一定的保护作用,作用机制可能与其保护血管内皮细胞,减轻脑缺血再灌注后的血脑屏障损伤有关。     

3,4,5-三甲氧基苯甲酸-8-(二乙胺基)-辛酯对大鼠脑血流及其自动调节功能的影响

用激光多谱勒血流仪连续测量脑血流量（CBF），观察3,4,5-三甲氧基苯甲酸-8-(二乙胺基)-辛酯(TMB-8)对麻醉大鼠CBF及脑血流自动调节功能的影响. 结果表明, TMB-8 0.5, 1.0和2.0 mg·kg^-1呈剂量依赖性地增加CBF 5%, 20% 和34%. 其中仅2.0 mg·kg^-1组使平均动脉压（MABP）降低6%. 而尼莫地平(Nim)0.01 mg·kg^-1在使CBF增加21%的同时，使MABP降低了27%. 麻醉大鼠脑血流自动调节的MABP低限是5.3 kPa. 在MABP 4.0 kPa时TMB- 8 2.0 mg·kg^-1能增加脑血流自动调节能力，而Nim 0.01 mg·kg^-1则无明显作用. 提示TMB-8增加CBF和增强脑血流自动调节能力是其抗脑缺血作用的机理之一.     

苦荞麦籽粒提取物对小鼠化学性肝损伤的影响

目的探讨苦荞麦籽粒提取物（FTGE）对肝脏的保护作用。方法FTGE对四氯化碳（CCl4）致急性肝损伤的作用：小白鼠60只，随机分为6组，每组10只。正常对照组、CCl4模型组灌胃给予等量纯化水，阳性对照组灌胃给予联苯双酯200 mg·kg^-1·d^-1，低剂量实验组、中剂量实验组、高剂量实验组分别灌胃给予FTGE 20，40和60 g·kg^-1·d^-1，各组均连续给药7 d。7 d后，除正常对照组外，其他各组小鼠均腹腔注射0.1% CCl4花生油溶液10 mL·kg^-1。禁食16 h，摘眼球取血，分离血清，测试血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）值。FTGE对D-半乳糖胺（D-Galn）致急性肝损伤的作用： 取60只小鼠，雌雄各半，分为6组，每组10只。正常对照组、D-Galn模型组灌胃给予0.9%氯化钠溶液 20 mL·kg^-1·d^-1，阳性对照组灌胃给予联苯双酯15 mg·kg^-1·d^-1，低剂量实验组、中剂量实验组、高剂量实验组分别灌胃给予FTGE 20，40和60 g·kg^-1，各组连续灌胃给药12 d，于末次给药后1 h，除正常对照组外，其他各组均腹腔注射10%D-Galn 800 mg·kg^-1，小鼠于腹腔注射D-Galn后禁食过夜，待16 h后断头处死动物。结果FTGE对CCl4和D-Galn导致的急性肝损伤小鼠有非常显著的降酶作用(P＜0.01)，且剂量越大，降酶作用越强。结论苦荞麦籽粒提取物对化学性肝损伤小鼠有明显的保护作用。     

烟碱和槟榔碱对大鼠颌下腺肌醇含量的影响

急性实验中，间隔5 min反复ip N受体激动剂烟碱0.5, 1.0, 1.0, 2.0, 2.0 mg·kg^-1可显著提高大鼠颌下腺中肌醇含量，并为N受体拮抗剂美加明1.0 mg·kg^-1对抗，为肌醇磷酸酶抑制剂氯化锂69.4 mg·kg^-1 ip翻转；一次性ip M受体激动剂槟榔碱200 mg·kg^-1也可显著提高颌下腺肌醇含量，并为M受体拮抗剂阿托品2.0 mg·kg^-1对抗；反复注射烟碱后，再ip不影响肌醇含量的槟榔碱50 mg·kg^-1，两者产生协同效应，进一步提高肌醇含量. 慢性实验中，每日2次sc烟碱2.0-5.0 mg·kg^-1或槟榔碱2.0-10.0 mg·kg^-1 14 d后，均可使大鼠颌下腺中肌醇含量显著降低.     

Mediation of calcitonin gene-related peptide in protection of ischemic preconditioning in rat hindlimbs.

AIM: To study modulation of calcitonin gene-related peptide (CGRP) in the protective effect of ischemic preconditioning on endothelial cells. METHODS: Rat hindlmbs were subjected to ischemia for 2 h, and endothelium-dependent vasorelaxation to acetylcholine (ACh) was examined in rat hindlimbs. RESULTS: Two hours of ischemia elicited no effect on vasoconstrictor responses to norepinephrine, but markedly impaired vasodilator responses to ACh. Ischemic preconditioning induced by 5-min aortic occlusion and 10-min blood reperfusion prevented the impairment of vasorelaxation to ACh due to long-term ischemia. The protection of ischemic preconditioning was abolished by repeated pretreatments with capsaicin to deplete CGRP. Acute application of capsaicin to evoke CGRP release or CGRP caused an ischemic preconditioning-like protection. CONCLUSION: Capsaicin-sensitive sensory nerves are involved in the protective effect of ischemic preconditioning on endothelial cells in the rat hindlimbs, and CGRP can mimic the protective effect of ischemic preconditioning in blood vessels.     

降钙素基因相关肽介导缺血预适应对溶血性磷脂酰胆碱损伤心肌的保护作用

研究心脏缺血预适应(PC)对溶血性磷脂酰胆碱(LPC)损伤心肌作用的影响，并探讨降钙素基因相关肽(CGRP)在PC中的作用. 离体大鼠心脏Langendorff法灌流，记录心率，冠脉流量，左室压和左室压最大上升速率(+dp/dt_max)，并测定灌流液中肌酸磷酸激酶(CPK)含量. 结果显示，LPC能降低各项心功能指标，并使CPK释放增加；PC(缺血5 min， 再灌5min，重复3次)能减轻LPC的损伤作用；PC的心肌保护作用可被选择性CGRP受体拮抗剂CGRP_8-37所取消；预先给予CGRP或辣椒素能产生与PC相同的心肌保护作用. 对照组, LPC, PC+LPC, CGRP_8-37, CGRP_8-37+PC+LPC, CGRP+LPC, CGRP_8-37+CGRP+LPC, 辣椒素+LPC组CPK释放量分别为0.26±0.05, 2.30±0.22, 0.25±0.03, 0.30±0.08, 2.60±0.15, 0.24±0.05, 2.70±0.20和0.25±0.07 μmol·min^-1·g^-1湿组织. 这些结果提示：1) PC对LPC所致心肌损伤具有保护作用；2) PC的保护作用是由CGRP所介导；3) CGRP或辣椒素可模拟PC的保护作用.     

The cardioprotective effects of nitroglycerin-induced preconditioning are mediated by calcitonin gene-related peptide

Previous investigations have shown that endogenous calcitonin gene-related peptide (CGRP) may play an important role in the mediation of ischemic preconditioning and that nitroglycerin evokes the release of CGRP. In the present study, we examined whether nitroglycerin provides a preconditioning stimulus, and whether the cardioprotective effects of nitroglycerin-induced preconditioning involve endogenous CGRP. Thirty minutes of global ischemia and 30 min of reperfusion caused a significant impairment of cardiac contractile function and an increased release of creatine kinase. Pretreatment with nitroglycerin at the concentration of 3x10(-7) or 10(-6) M for 5 min produced a significant improvement of cardiac function and a decrease in the release of creatine kinase. The content of CGRP-like immunoreactivity in coronary effluent was increased during nitroglycerin perfusion. However, the cardioprotection afforded by nitroglycerin was abolished by CGRP-(8-37) (10(-7) M), a selective CGRP receptor antagonist. Pretreatment with capsaicin (50 mg/kg, s.c.), which specifically depletes the transmitter content of sensory nerves, also abolished the protective effects of nitroglycerin and markedly reduced the release of CGRP from the heart during nitroglycerin perfusion. These findings suggest that nitroglycerin-induced preconditioning is related to stimulation of CGRP release in rat hearts.     

Delayed cardioprotection by intestinal preconditioning is mediated by calcitonin gene-related peptide

Previous studies have shown that nitric oxide and calcitonin gene-related peptide (CGRP) are involved in mediation of the delayed cardioprotection of ischemic or pharmacological preconditioning, and nitric oxide can evoke the release of CGRP. In the present study, we examined the role of CGRP in nitric oxide-mediated delayed cardioprotection by brief intestinal ischemia in rats. The serum concentration of creatine kinase and infarct size were measured after 45-min coronary artery occlusion and 180-min reperfusion. Ischemic preconditioning was induced by six cycles of 4-min ischemia and 4-min reperfusion of the small intestine. Pretreatment with intestinal ischemic preconditioning for 24, 48, or 72 h significantly reduced infarct size and creatine kinase release, and the effects of ischemic preconditioning were completely abolished by L-nitroarginine methyl ester (L-NAME, 10 mg/kg, i.p.), an inhibitor of nitric oxide synthase, or by pretreatment with capsaicin (50 mg/kg, s.c.), which selectively depletes transmitters in capsaicin-sensitive sensory nerves. Intestinal preconditioning caused a significant increase in plasma concentrations of CGRP, and the effect was also abolished by L-NAME or capsaicin. These results suggest that the delayed cardioprotection afforded by intestinal ischemic preconditioning is mediated by endogenous CGRP via the nitric oxide pathway.     

孕酮对吗啡位置偏爱大鼠下丘脑中内阿片肽水平的影响

目的观察孕酮对于吗啡所致奖赏效应及下丘脑中内阿片肽水平的影响。方法建立吗啡条件性位置偏爱(CPP)模型,采用放射免疫法测定大鼠下丘脑中β-内啡肽(β-EP)、亮氨酸脑啡肽(L-EK)和强啡肽A(DynA)的含量。结果与生理盐水对照组比较,5mg·kg-1吗啡可诱导大鼠产生稳定的CPP效应(P<0.01),15mg·kg-1孕酮本身不产生CPP效应,但能抑制吗啡的CPP效应。与对照组比较,吗啡CPP形成时,下丘脑中β-EP和L-EK水平明显降低(P<0.05),DynA水平明显升高(P<0.05)。与吗啡组比较,合用15mg·kg-1孕酮可使下丘脑中β-EP和L-EK水平明显升高(P<0.05),DynA水平明显降低(P<0.05)。结论孕酮可以有效抑制吗啡CPP效应,其机制可能与逆转吗啡诱导的下丘脑中β-EP、L-EK和DynA水平的变化有关。     

Protection of calcitonin gene-related peptide-mediated preconditioning against lysophosphatidylcholine-induced myocardial injury in isolated rat hearts

研究心脏缺血预适应（ＰＣ）对溶血性磷脂酰胆碱（ＬＰＣ）损伤心肌作用的影响，并探讨降钙素基因相关肽（ＣＧＲＰ）在ＰＣ中的作用．离体大鼠心脏Ｌａｎｇｅｎｄｏｒｆ法灌流，记录心率，冠脉流量，左室压和左室压最大上升速率（＋ｄｐ／ｄｔｍａｘ），并测定灌流液中肌酸磷酸激酶（ＣＰＫ）含量．结果显示，ＬＰＣ能降低各项心功能指标，并使ＣＰＫ释放增加；ＰＣ（缺血５ｍｉｎ，再灌５ｍｉｎ，重复３次）能减轻ＬＰＣ的损伤作用；ＰＣ的心肌保护作用可被选择性ＣＧＲＰ受体拮抗剂ＣＧＲＰ８－３７所取消；预先给予ＣＧＲＰ或辣椒素能产生与ＰＣ相同的心肌保护作用．对照组，ＬＰＣ，ＰＣ＋ＬＰＣ，ＣＧＲＰ８－３７，ＣＧＲＰ８－３７＋ＰＣ＋ＬＰＣ，ＣＧＲＰ＋ＬＰＣ，ＣＧＲＰ８－３７＋ＣＧＲＰ＋ＬＰＣ，辣椒素＋ＬＰＣ组ＣＰＫ释放量分别为０．２６±０．０５，２．３０±０．２２，０．２５±０．０３，０．３０±０．０８，２．６０±０．１５，０．２４±０．０５，２．７０±０．２０和０．２５±０．０７μｍｏｌ·ｍｉｎ－１·ｇ－１湿组织．这些结果提示：１）ＰＣ对ＬＰＣ所致心肌损伤具有保护作用；２）ＰＣ的保护作用是由ＣＧＲＰ所介导；３）ＣＧＲＰ或辣椒素可模拟ＰＣ的保护作?     

降钙素基因相关肽:一种调节预适应的内源性中介物(英文)

心脏遭受短暂缺血或高温处理后均产生早期和延迟保护效应.缺血预适应的心脏保护作用与内源性活性物质有关.辣椒素敏感的感觉神经的主要递质降钙素基因相关肽(CGRP)介导缺血预适应的早期和延迟保护作用.CGRP介导的预适应能保护内皮细胞.热应激的早期和延迟保护也与内源性CGRP释放有关.某些药物如硝酸甘油诱导的预适应可能与其促CGRP释放有关.这些结果表明CGRP可能是一种内源性心肌保护物质,并在预适应的保护效应中起重要作用.     

Delayed preconditioning by cardiac ischemia involves endogenous calcitonin gene-related peptide via the nitric oxide pathway

Previous investigations have shown separately that calcitonin gene-related peptide (CGRP) or nitric oxide (NO) is involved in mediation of ischemic preconditioning. In the present study, we tested interactions of CGRP with NO in mediation of delayed preconditioning. In Sprague-Dawley rats, ischemia-reperfusion injury was induced by 45-min occlusion followed by 3-h reperfusion of coronary artery, and preconditioning was induced by four cycles of 3-min ischemia and 5-min reperfusion. Infarct size, plasma creatine kinase activity, the plasma level of NO and CGRP, and the expression of CGRP mRNA in dorsal root ganglion were measured. Pretreatment with preconditioning significantly reduced infarct size and the release of creatine kinase during reperfusion, and caused a significant increase in the expression of CGRP mRNA, concomitantly with an elevation in the plasma level of CGRP and NO. The effects of preconditioning were completely abolished by administration of L-nitroarginine methyl ester (L-NAME, 10 mg/kg, i.p.), an inhibitor of NO synthase. Pretreatment with capsaicin (50 mg/kg, s.c.), which depletes transmitters in capsaicin-sensitive sensory nerves, also blocked the cardioprotection of preconditioning and reduced the synthesis and release of CGRP, but did not affect the concentration of NO. The present results suggest the delayed protection afforded by ischemic preconditioning is also mediated by endogenous CGRP via the NO pathway in rat heart.     

CGRP、K_(ATP)通道和脊神经在鞘内注射吗啡预处理减轻大鼠心肌缺血后损伤中的作用

目的探讨降钙素基因相关肽(CGRP)、ATP敏感性钾离子通道(KATP通道)和脊神经在鞘内注射吗啡预处理对在体大鼠心肌缺血/再灌注损伤中的保护作用。方法♂SD大鼠60只,建立鞘内置管和心肌缺血/再灌注损伤模型,随机分为10组,每组6只:对照组(CON,生理盐水)、二甲亚砜组(DMSO,GLI的溶剂)、CGRP8-37组(CGRP受体阻滞剂,3nmol.kg-1)、格列苯脲组(GLI,KATP通道阻滞剂,0.3 mg.kg-1)、利多卡因组(LID,1%盐酸利多卡因10μl)、鞘内注射吗啡预处理组(MPC,3×1μg.kg-1)、CGRP8-37+MPC组、GLI+MPC组、LID+MPC组、GLI+LID组。观察指标包括:平均动脉压(MAP)、心率(HR),计算平均动脉压和心率乘积(RPP);心肌缺血危险区(AAR)、梗死区(IS)的体积、心肌梗死面积以IS/AAR表示。结果与CON组比较,MPC组、LID组、LID+MPC组和GLI+LID组的IS和IS/AAR均明显下降(P<0.05,P<0.01);与MPC组比较,CGRP8-37+MPC组、GLI+MPC组和LID+MPC组的IS和IS/AAR均明显增加(P<0.01)。结论外周CGRP的释放、KATP通道和脊神经可能参与了鞘内注射吗啡预处理减轻大鼠心肌缺血后损伤的作用。     

Inhibition of cardiac tumor necrosis factor-alpha production by calcitonin gene-related peptide-mediated ischemic preconditioning in isolated rat hearts

Previous investigations have demonstrated that calcitonin gene-related peptide (CGRP) plays an important role in the mediation of ischemic preconditioning in rats. In the present study, we examined signal transduction pathways of CGRP-mediated ischemic preconditioning. Thirty minutes of global ischemia and 40 min of reperfusion caused a dramatic decrease in myocardial function, and a significant increase in the release of cardiac creatine kinase in the coronary effluent and in the content of tumor necrosis factor-alpha (TNF-alpha) in myocardial tissues. However, ischemic preconditioning (three cycles of 5-min ischemia and 5-min reperfusion) or pretreatment with CGRP for 5 min dramatically improved the recovery of cardiac function, and reduced the release of cardiac creatine kinase and the TNF-alpha content. The effect of ischemic preconditioning was abolished by CGRP-(8-37), the selective CGRP receptor antagonist, and by capsaicin, which depletes sensory nerve neurotransmitter content, but was unaltered by treatment with glibenclamide, a blocker of the ATP-sensitive potassium (K(ATP)) channel. The protective effects of exogenous CGRP-induced preconditioning were also not blocked by glibenclamide. These results suggest that the cardioprotective effects afforded by CGRP-mediated ischemic preconditioning are related to inhibition of cardiac TNF-alpha production, but not to activation of the K(ATP) channel.