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.     

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.     

Role of calcitonin gene-related peptide in ischaemic preconditioning in diabetic rat hearts

1. It has been suggested that calcitonin gene-related peptide (CGRP) is involved in the protection provided by ischaemic preconditioning in rat hearts and that ischaemic preconditioning is absent in diabetic rat hearts. 2. In the present study, we tested the relationship between sensory nerve function and ischaemic preconditioning in diabetic rats. 3. In 4- and 8-week diabetic rats and age-matched non- diabetic controls, 30 min global ischaemia and 40 min reperfusion caused a significant decrease in cardiac function and a marked increase in creatine kinase (CK) release. Ischaemic preconditioning, by three cycles of 5 min ischaemia and 5 min reperfusion, improved the recovery of cardiac function and decreased CK release during reperfusion in 4-week diabetic rat hearts. However, the cardioprotection afforded by ischaemic preconditioning was lost in 8-week diabetic rat hearts. Pretreatment with CGRP for 5 min also significantly improved the recovery of cardiac function and decreased CK release in rats subjected to 4 or 8 weeks of diabetes. 4. The content of CGRP in the coronary effluent during ischaemic preconditioning was significantly increased in 4-week diabetic rat hearts (P < 0.05). However, only a slight increase in the release of CGRP was shown in 8-week diabetic rat hearts (P > 0.05). 5. In summary, the present results suggest that the protection afforded by ischaemic preconditioning is attenuated in diabetic rats and that the change may be related to the reduction in CGRP release in diabetic rat hearts.     

降钙素基因相关肽在一氧化氮介导热应激诱导心肌延迟预适应中的作用

目的：研究一氧化氮－降钙素基因相关肽途径是否参与热应激诱导的心肌延迟预适应。方法：采用Langendorff装置灌注离体心脏。心脏低温（4℃）保存4h后,再灌注40min(37℃）。实验前24h大鼠进行高温处理（直肠温度42℃,15min)。记录心率,冠脉流量、左室内压以及最大变化速率,并测定血浆降钙素基因相关肽（CGRP）浓度和冠脉流出液中肌酸激酶（CK）释放量。结果：热应激能显著增强心肌停搏液的保护作用,减少CK释放量,并升高血浆CGRP浓度。这些作用能被预先给予亚硝基精氨酸甲酯及辣椒素所取消。结论：一氧化氮参与了对大鼠心脏的延迟保护,其作用是由内源性CGRP所介导。     

Involvement of alpha-calcitonin gene-related peptide in monophosphoryl lipid A-induced delayed preconditioning in rat hearts

Recent study has shown that monophosphoryl lipid A-induced delayed preconditioning enhanced preservation with cardioplegia and that the protective effects of monophosphoryl lipid A were related to stimulation of calcitonin gene-related peptide (CGRP) release. The purpose of the present study was to explore whether the elevated release of CGRP induced by monophosphoryl lipid A is secondary to stimulation of CGRP synthesis via the nitric oxide (NO) pathway and to characterize the isoform of CGRP. Sprague-Dawley rats were pretreated with monophosphoryl lipid A 24 h before the experiment, and then the left main coronary artery of rat hearts was subjected to 1 h occlusion followed by 3 h reperfusion. Infarct size, plasma creatine kinase activity, the plasma level of CGRP, and the expression of CGRP isoforms (alpha- and beta-CGRP) mRNA in lumbar dorsal root ganglia were measured. Pretreatment with monophosphoryl lipid A (500 microg/kg, i.p.) significantly reduced infarct size and creatine kinase release. Monophosphoryl lipid A caused a significant increase in the expression of alpha-CGRP mRNA, but not of beta-CGRP mRNA, concomitantly with an increase in plasma concentrations of CGRP, and the increased level of CGRP expression happened before stimulation of CGRP release. The effect of monophosphoryl lipid A was completely abolished by pretreatment with L-nitroarginine methyl ester (L-NAME, 10 mg/kg, i.p.), an inhibitor of NO synthase or capsaicin (50 mg/kg, s.c.), which selectively depletes transmitters in capsaicin-sensitive sensory nerves. The results suggest that the delayed cardioprotection afforded by monophosphoryl lipid A involves the synthesis and release of CGRP via the NO pathway, and that the protection is mainly mediated by the alpha-CGRP isoform.     

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?     

降钙素基因相关肽在前列腺素介导豚鼠心脏缺血预适应中的作用(英文)

目的:研究降钙素基因相关肽与前列腺素在豚鼠心脏缺血预适应中的相互作用。方法:采用Langen-dorff方法灌注豚鼠离体心脏。记录心率、冠脉流量、左室内压以及最大变化速率,并测定冠脉流出液中降钙素基因相关肽(CGRP)与6-酮-PGF_(1α)的释放量。结果:内皮素-1(200 pmoL)引起心功能下降,表现为冠脉流量、心率、左室内压及其最大变化速率降低。缺血预适应可明显减轻内皮素-1引起的心脏损伤,同时预适应期间CGRP与6-酮-PGF_(1α)的释放量明显增加。应用辣椒素耗竭内源性CGRP后,缺血预适应的保护作用被取消。选择性CGRP_1受体拮抗剂CGRP_(8-37)100nmol/L也能取消缺血预适应的保护作用。环氧化酶抑制剂吲哚美辛(10μmol/L)可取消缺血预适应的保护作用,同时缺血预适应促进CGRP与6-酮-PGF_(1α)释放的作用也被取消。结论:前列腺素参与了缺血预适应对豚鼠心脏的保护作用,前列腺素的作用是由CGRP所介导。     

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。     

降钙素基因相关肽与高血压

感觉神经广泛分布于全身血管组织 ,通过释放多种血管活性神经肽调节心血管功能。降钙素基因相关肽是辣椒素敏感感觉神经的重要肽类递质 ,为目前已知的舒血管作用最强的物质。在高血压患者及多种实验性高血压动物中降钙素基因相关肽的合成和释放均发生改变 ,对高血压的发生、发展起着重要的作用     

A role for the sensory neuropeptide calcitonin gene-related peptide in endothelial cell proliferation in vivo

BACKGROUND AND PURPOSE

We have tested the hypothesis that calcitonin gene-related peptide (CGRP) is a mediator of capsaicin-induced angiogenesis in vivo.

EXPERIMENTAL APPROACH

In a series of experiments, the knee joints of rats were injected with CGRP, capsaicin or vehicle control. Groups of animals (n = 6) were treated with the CGRP receptor antagonist BIBN4096BS and/or the NK₁ receptor antagonist SR140333. Endothelium, proliferating endothelial cell nuclei and macrophages were identified 24 h later in the synovium by immunohistochemistry and quantified by image analysis. mRNA for the receptors for CGRP and adrenomedullin were sought in normal and inflamed rat and human synovia using RT-PCR.

KEY RESULTS

Intra-articular CGRP injection increased the endothelial cell proliferation index, whereas macrophage infiltration and knee joint diameters were similar to saline-injected controls. CGRP-induced endothelial cell proliferation was dose-dependently inhibited by BIBN4096BS. mRNA for adrenomedullin and the CGRP receptor subunits were detected in normal and inflamed human and rat synovia. In capsaicin-induced synovitis, the increased endothelial cell proliferation index was partially blocked by administration of NK₁ or CGRP antagonists individually and was reduced to the level of saline controls by coadministration of both receptor antagonists.

CONCLUSIONS AND IMPLICATIONS

These data support the hypothesis that CGRP stimulates angiogenesis in vivo directly by activating CGRP receptors. Capsaicin-induced endothelial cell proliferation was completely blocked by coadministration of CGRP and NK₁ receptor antagonists, indicating that both CGRP and substance P may contribute to angiogenesis in this model of synovitis.     

降钙素基因相关肽对大鼠小肠缺血预适应的保护作用

目的探讨降钙素基因相关肽(CGRP)在大鼠小肠缺血预适应中的作用及意义。方法①健康Wistar雄性大鼠,体质量(280±30)g,分为3组(各8只),对照组(CON):仅分离肠系膜上动脉(SMA),不夹闭,观察90 min;缺血再灌组(I/R):分离SMA,夹闭30 min,再灌注60 min,结束实验;缺血预适应组(IP):分离SMA,夹闭SMA 5 min反复3次,然后再夹闭30 min,再灌注60 min,结束实验。②利用放射免疫法测定CGRP含量,以乳酸脱氢酶(LDH)、丙二醛(MDA)含量变化和形态学变化为指标,评价缺血再灌注损伤。结果缺血预适应可明显抑制大鼠小肠缺血再灌注损伤后LDH的水平增高,降低MDA的含量(P<0.01),保护小肠黏膜不受损伤。结论CGRP为大鼠小肠缺血再灌注损伤中关键性介质之一,缺血预适应可提高大鼠小肠缺血再灌注后CGRP的水平,对抗缺血再灌注损伤。     

Monophosphoryl lipid A-induced delayed preconditioning is mediated by calcitonin gene-related peptide

The delayed preconditioning of the heart by monophosphoryl lipid A is mediated by endogenous nitric oxide (NO), and the cardioprotection afforded by nitroglycerin is related to stimulation of calcitonin gene-related peptide (CGRP) release. The objective of this study was to explore whether improvement of preservation with cardioplegia by monophosphoryl lipid A is mediated by CGRP. In addition, we examined the effect of monophosphoryl lipid A on the tumor necrosis factor-alpha (TNF-alpha) content of myocardial tissues. The isolated rat heart was perfused in the Langendorff mode. Heart rate, coronary flow, left-ventricular pressure, and its first derivatives (+/-dp/dt(max)) were recorded, and plasma levels of NO and CGRP, the release of creatine kinase in coronary effluent and the content of TNF-alpha in myocardial tissues were measured. Hypothermic ischemia for 4 h caused a decline in cardiac function, and an increase in the release of creatine kinase and in the content of TNF-alpha. Pretreatment with monophosphoryl lipid A (500 microg/kg, i.p.) for 24 h improved the recovery of cardiac function and reduced the release of creatine kinase concomitantly with a decrease in the content of cardiac TNF-alpha. Monophosphoryl lipid A markedly increased plasma concentrations of CGRP and NO. After pretreatment with L-nitroarginine methyl ester (L-NAME), the cardioprotection and the increased release of NO and CGRP induced by monophosphoryl lipid A were abolished. Capsaicin also abolished the cardioprotection and the increased release of CGRP induced by monophosphoryl lipid A, but did not affect the content of NO. The results suggest that monophosphoryl lipid A-induced preconditioning enhances preservation with cardioplegia and that the protective effects of monophosphoryl lipid A are related to stimulation of CGRP release.     

内毒素引起离体大鼠脊髓降钙素基因相关肽释放

本文在离体灌流大鼠脊髓片观察内毒素对感觉神经元中枢端末梢降钙素基因相关肽（ＣＧＲＰ）释放的影响．结果显示内毒素及其主要毒性成分Ａ脂均能浓度依赖性地引起ＣＧＲＰ释放，内毒素的作用可被内毒素抑制剂与钠通道阻断剂河豚毒素所阻断．采用辣椒素预温育使感觉神经末梢递质耗竭，或用辣椒素受体阻断剂ｃａｐｓａｚｅｐｉｎｅ均能显著抑制内毒素引起ＣＧＲＰ释放的作用．上述结果提示内毒素是通过其主要毒性成分＃ＦＳＡ＃ＦＫ脂，刺激辣椒素敏感的感觉神经末梢而释放ＣＧＲＰ的     

Protective effects of nitroglycerin-induced preconditioning mediated by calcitonin gene-related peptide in rat small intestine

Previous studies of myocardium have shown that ischemic preconditioning could be mimicked by nitroglycerin through stimulating the release of calcitonin gene-related peptide (CGRP). The present study examined whether nitroglycerin could also provide a preconditioning stimulus in the peripheral vascular bed (the anse intestinalis of rat), and whether endogenous CGRP is involved in this process. The model of in situ perfusion was prepared with rat small intestine. One hour of ischemia and 15 min of reperfusion caused a significant impairment of intestinal morphology and an increase in the release of both lactate dehydrogenase and malondialdehyde. Pretreatment with nitroglycerin, 10⁻⁷, 3×10⁻⁷, 10⁻⁶ M for 5 min produced a significant improvement of intestinal tissue morphology and a decrease in the release of both lactate dehydrogenase and malondialdehyde. However, the protection afforded by nitroglycerin was abolished by CGRP-(8-37), a selective CGRP acceptor antagonist. Pretreatment with capsaicin, which specifically depletes the transmitter content of sensory nerves, also abolished the protection by nitroglycerin. In addition, the content of CGRP-like immunoreactivity in the effluent was increased during nitroglycerin perfusion. On the other hand, the results from the in vivo experiment showed that nitroglycerin (i.v. 0.13 mg/kg) injected 5 min before prolonged ischemia could provide significant protection against the injury caused by 30-min ischemia and 1-h reperfusion in the rat small intestine, but would also cause a significant increase in the levels of CGRP in the plasma. All these findings suggest that nitroglycerin-induced preconditioning is related to stimulation of CGRP release in the rat small intestine.     

Early and delayed cardioprotection by heat stress is mediated by calcitonin gene-related peptide

Brief ischaemia or heat stress protects the myocardium against ischaemia-reperfusion injury. Heat stimulus evokes release of sensory nerve transmitters, including calcitonin gene-related peptide (CGRP). Since CGRP has been shown to play an important role in the mediation of ischaemic preconditioning, the present study examined whether early or delayed preconditioning induced by retrograde hyperthermic perfusion in vitro or by whole-body hyperthemia in vivo also involves endogenous CGRP. Isolated rat hearts were perfused in the Langendorff mode and subjected to 30 min global ischaemia and 30 min reperfusion. Heart rate, coronary flow, left ventricular pressure and its first derivatives (±dp/dt) were recorded and the CGRP-like immunoreactivity (CGRP-LI) content and the release of creatine kinase (CK) during reperfusion were measured. Retrograde hyperthermic perfusion (42 °C) for 5 min improved the recovery of cardiac function, decreased the release of CK and elevated the content of CGRP-LI in the coronary effluent. CGRP_8–37 (10^–7 mol/l), a selective CGRP receptor antagonist, abolished the cardioprotection by heat stress. Pretreatment with capsaicin (50 mg/kg s.c.), which specifically depletes sensory nerve transmitter content, abolished both the cardioprotection and the increased release of CGRP-LI. Whole-body hyperthermia (42 °C for 15 min) caused an increase in the plasma concentration of CGRP-LI. Early or delayed protection was shown in the hearts obtained from the animals subjected to whole-body hyperthermia 10 min or 48 h before the experiments. The early or delayed protection by heat stress was also abolished by pretreatment with capsaicin. The present study suggests that, in the rat, the early and delayed cardioprotection induced by heat stress involves endogenous CGRP. Received: 31 December 1998 / Accepted: 6 April 1999     

降钙素基因相关肽介导硝酸甘油增强心停搏液的保护作用(英文)

目的:研究硝酸甘油增强心停搏液的保护作用与促进降钙素基因相关肽释放的关系。方法:在StThomas Hospital心停搏液条件下,离体心脏低温缺血4h后再灌40min,记录心率、冠脉流量及心功能,并测定灌注液中降钙素基因相关肽(CGRP)的浓度及肌酸激酶(CK)的释放量。结果:硝酸甘油(0.1或1μmol/L)改善心功能,降低CK释放,同时促进CGRP的释放。CGRP(5或10nmol/L)也改善心功能及降低CK释放。预先用辣椒素耗竭感觉神经递质后。硝酸甘油的心肌保护和升高灌注液中CGRP浓度作用消失。选择性CGRP受体拮抗剂CGRP_(8-37)也能取消硝酸甘油的心肌保护作用。格列苯脲对硝酸甘油和CGRP的心保护作用均无影响。结论:硝酸甘油增强心停搏液的保护作用是通过内源性CGRP所介导,其保护作用与ATP敏感的钾通道无关。     

缺血预适应对大鼠小肠缺血再灌注损伤的保护作用(英文)

观察预适应对大鼠小肠缺血再灌的保护作用及对内源性神经递质降钙素基因相关肽 (CGRP)释放的影响 .选用雄性 Wistar大鼠 40只 (2 75- 32 5g) ,实验分在体和离体两部分 .(1 )在体部分 :30 min的小肠缺血和 60 min的再灌流可引起小肠湿重干重比值 (WW/DW)增高 ,血中乳酸脱氢酶 (LDH)活性 ,丙二醛 (MDA)含量显著增加 .3次 8min缺血及1 0 min再灌流预适应可降低前述缺血再灌引起的WW/DW,LDH活性及 MDA含量增高 ,但各组血液中 CGRP水平未见明显变化 .(2 )离体部分 :肠系膜上动脉插管连接灌流装置 .肠系膜上静脉插管收集流出液 .小肠灌流 1 0 min后 ,反复 3次 8min阻断灌流及 1 0 min再灌流预适应模型可使流出液中的 CGRP显著增加〔(1 .30± 0 .0 8) vs(0 .68±0 .0 5) μg· L-1,P<0 .0 1〕.结果提示 :缺血预适应对小肠缺血再灌损伤具有显著保护作用 ,CGRP可能是预适应的一种内源性神经介质     

降钙素基因相关肽介导吴茱萸次碱的降压作用

目的研究吴茱萸次碱在自发性高血压大鼠(SHR)的降压作用,并探讨其效应是否由降钙素基因相关肽(CGRP)介导。方法灌胃给予不同剂量吴茱萸次碱(10、20和40 mg.kg-1.d-1),连续给药14 d。测量大鼠动脉尾收缩血压,分离血浆检测CGRP浓度(放免分析法),切取胸腰段背根神经节检测CGRP mRNA的表达水平(RT-PCR法)。结果吴茱萸次碱能显著降低SHR血压,且呈剂量依赖性[对照组与3个剂量吴茱萸次碱组的血压分别为(187±4)、(168±6)、(153±2)和(143±5)mmHg]。吴茱萸次碱能同时剂量依赖性增加血浆CGRP浓度及上调背根神经节中CGRP mRNA的表达。氯沙坦也显著降低SHR动脉压[(187±4)vs(131±2)mmHg],但增加CGRP血浆浓度及上调CGRP mRNA的表达作用弱于吴茱萸次碱。结论吴茱萸次碱能显著降低SHR的血压,其机制与促进CGRP的合成与释放有关。     

氯沙坦和哌唑嗪调节早期高血压大鼠体内降钙素基因相关肽反应的差异

目的：探讨高血压早期大鼠体内降钙素基因相关肽（CGRP）的变化,并观测两类降压药物,氯沙坦或哌唑嗪在降压过程中对CGRP的反应差异。方法：采用经典的两肾一夹型高血压大鼠（Goldblatt,2K1C）为研究模型,夹尾法测定大鼠清醒状态下血压,通过公式计算出平均动脉压;放射免疫法血浆内CGRP和血管紧张素Ⅱ（AngⅡ）的含量。反转录聚合连反应（RT-PCR）测定脊髓背根神经节中CGRP mRNA的表达。结果：收缩压、平均动脉压在结扎肾动脉10d后较对照组快速升高（P〈0．01）,给予氯沙坦或哌唑嗪治疗5d后,血压明显降低（P〈0．01）;实验末,高血压未治疗组血浆中AngⅡ、CGRP浓度（P〈0．01,P〈O．01）和脊髓背根神经节中的CGRP mRNA的表达明显升高（P〈0．05）,高血压氯沙坦治疗组可进一步升高大鼠血浆中AngⅡ、CGRP浓度（P〈0．01,P〈0．01）和脊髓背根神经节中的CGRP mRNA的表达（P〈0．05）;但在高血压哌唑嗪治疗组大鼠血浆中AngⅡ变化不显著（P〉0．05）,但CGRP浓度和脊髓背根神经节中的CGRP mRNA的表达与未治疗组相比显著降低（P〈0．05,P〈0．01）。结论：在肾血管性高血压早期含CGRP感觉神经功能存在代偿性增高,氯沙坦或哌唑嗪的不同降压机制也可能与其影响体内CGRP合成和释放差异有关。     

睾丸切除大鼠去甲肾上腺素、降钙素基因相关肽和乙酰胆碱血管效应的变化

目的:研究雄性大鼠去势1至4个月后,血管活性物质对离体动脉作用的改变.方法:采用双侧睾丸切除的雄性大鼠,分为假手术组(SHAM)、去势组(ORDX)和雄激素替代组(TP).于替代后 1、2及 4个月时,取胸主动脉、肺动脉及尾动脉,进行离体血管功能实验,观察对去甲肾上腺素(NE)、降钙素基因相关肽(CGRP)及乙酰胆碱(ACh)的反应.结果:去势 1个月后,NE、ACh和 CGRP引起的大鼠离体动脉收缩和舒张反应无明显改变,仅在主动脉,TP组CGRP的舒张效应曲线明显左移;2个月后,NE、ACh、CGRP引起的大鼠离体动脉收缩和舒张反应无明显改变;4个月后,对 CGRP和 ACh的舒张反应无明显改变,但ORDX组对NE引起的主动脉收缩反应曲线左移,替代后恢复.结论:相对于雌激素,雄激素对血管的保护作用较弱,其机制可能是通过抑制血管的收缩反应.