Release of calcitonin gene-related peptide in cardiac anaphylaxis

We have investigated the antigen-stimulated release of calcitonin gene-related peptide (CGRP) from ovalbumin-sensitized guinea-pig isolated hearts and the interaction with other mediators of anaphylaxis released concomitantly. It was found that antigen challenge caused a significant increase of CGRP release (from basal 31.2 ± 2.9 to 51.6 ± 4.9 fmol/5 min). Anaphylactic CGRP release was significantly attenuated in the presence of the cyclooxygenase inhibitor indomethacin while the 5-lipoxygenase inhibitor Bay-X1005 ((R)-2-[4-quinolin-2-yl-methoxy)phenyl]-2-cyclopentyl acetic acid) had no significant effect. Combined treatment with the histamine receptor (H₁,H₂) antagonists mepyramine and cimetidine also significantly attenuated anaphylactic release of CGRP. Under control conditions antigen injection increased release of cysteinyl-leukotrienes (LT), thromboxane (TXB₂) and 6-keto-prostaglandin (PG)F_1α from basal values of 0.96 ± 0.09, 2.7 ± 0.7 and 3.4 ± 0.28 ng/5 min respectively, to 5.9 ± 0.9, 48.4 ± 3.4 and 6.9 ± 1.4 ng/5 min. Indomethacin abolished the release of cyclooxygenase products of arachidonate metabolism and simultaneously increased cysteinyl-LT release significantly (8.8 ± 1.4 ng/5 min). Conversely Bay-X1005 completely abolished cysteinyl-LT release and had no significant effect on anaphylactic release of TXB₂ and 6-keto-PGF_1α. Simultaneous blockade of H₁ and H₂ receptors abolished release of 6-keto-PGF_1α, while release of TXB₂ and cysteinyl-LT was not significantly affected. The results indicate that CGRP is not a primary mediator of the immediate hypersensitivity reaction of the heart, but is in turn released by arachidonic acid metabolites of the cyclooxygenase pathway and histamine. In contrast, LT obviously do not contribute to anaphylactic CGRP release. CGRP is a potent coronary vasodilator and could act as endogenous functional antagonist of vasoconstrictor mediators also released during cardiac anaphylaxis such as cysteinyl-LT, platelet activating factor and TXA₂. Received: 8 May 1996 / Accepted: 11 October 1996     

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.     

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。     

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。     

降钙素基因相关肽对人皮肤成纤维细胞增殖的影响

目的探讨降钙素基因相关肽(CGRP)在不同浓度下对人皮肤成纤维细胞(Fb)增殖的影响。方法以含不同浓度的降钙素基因相关肽(CGRP)培养基培养成纤维细胞,在不同时间用细胞计数板进行细胞计数,四甲基偶氮唑盐比色法(MTT)法检测细胞的活性,选择最适浓度生长因子干预的细胞,用流式细胞仪检测细胞的DNA倍体情况及细胞周期,对所得数据进行统计学处理。结果降钙素基因相关肽(CGRP)促皮肤成纤维细胞(Fb)增殖作用的强度与CGRP的浓度和作用时间有关,在一定范围内随降钙素基因相关肽浓度递增作用增强,时间是在48 h促增殖作用最强。结论降钙素基因相关肽能够促进人皮肤成纤维细胞的增殖。     

Effects of capsaicin,tachykinins, calcitonin gene-related peptide and bradykinin in the pig iris sphincter muscle

Summary Capsaicin-sensitive sensory neurons of the rabbit iris, by releasing tachykinins, exert a major role in the control of pupil motility in response to various noxious stimuli. However, the contribution of sensory innervation to the regulation of iris smooth muscle tone in other mammals species is not known. We have studied the effects produced by electrical field stimulation, capsaicin, substance P, neurokinin A, calcitonin gene-related peptide (CGRP), and bradykinin in the isolated iris sphincter muscle of the pig.Capsaicin (10 M): a) contracted the isolated sphincter muscle and; b) released immunoreactivity for substance P (SP-LI) and CGRP (CGRP-LI) from this preparation. These two effects were no longer observed at the second exposure to the drug. Electrical field stimulation (10 Hz, 60 V, 0.5 ms for 5 s) produced a biphasic contractile response. The rapid component was inhibited by atropine (1 M), while the delayed response was blocked by previous exposure to capsaicin (10 M).Substance P and neurokinin A consistently produced contraction of the pig iris sphincter muscle, substance P being more potent than neurokinin A. CGRP induced a contractile response in more than 50% of the preparations. The tachykinin antagonist [D-Argl, D-Trp^7,9, Leu¹¹-substance P (3 M) blocked: a) the effect of substance P (1 nM); b) the delayed response to electrical field stimulation and; c) reduced by more than 50% response to capsaicin. Bradykinin (10 M) failed to release either SP-LI or CGRP-LI. The contractile response evoked by bradykinin was unaffected by in vitro pretreatment with capsaicin (10 M).The existence in the pig iris of capsaicin-sensitive sensory fibres releasing neuropeptides and thus regulating sphincter muscle tone is proposed. Send offprint requests to Dr. P. Geppetti at the above address     

应激状态下大鼠颞颌关节内降钙素基因相关肽的变化

目的通过观察应激状态下髁突软骨细胞内降钙素基因相关肽(CGRP)的变化,探讨应激对颞下颌关节的可能致病机制。方法建立应激动物模型,运用RT-PCR技术检测对照组、应激组与药物对照组大鼠髁突软骨细胞CGRPmRNA表达。结果在第10天时应激组CGRPmRNA表达最高。药物对照组CGRPmRNA的表达也有升高。第20天时应激组CGRPmRNA与第10天时相比显著降低(P<0.05),但高于对照组(P<0.05)。药物对照组水平接近对照组(P>0.05)。30 d时应激组和药物对照组CGRP水平回落到对照组水平(P>0.05)。结论应激可能在TMD形成过程中起着重要作用。     

The cardioprotection of calcitonin gene-related peptide-mediated preconditioning

Preconditioning induced by brief ischemia or hyperthermia or some drugs shows two phases, early and delayed protection. The cardioprotection afforded by preconditioning is related to stimulation of endogenous mediators release. Calcitonin gene-related peptide (CGRP), a major transmitter of capsaicin-sensitive sensory nerves, has recently been shown to play an important role in mediation of the preconditioning induced by brief ischemia or hyperthermia or by some drugs, and alpha-CGRP seems to play a major role in the mediation of delayed preconditioning. It has been shown that the cardioprotection afforded by CGRP-mediated preconditioning is due to inhibition of cardiac tumor necrosis factor-alpha (TNF-alpha) production, but not to the activation of the K(ATP) channel.     

肺心病血浆内皮素-1与心钠素和降钙素基因相关肽水平的临床实验分析

目的:分析慢性肺源性心脏病(肺心病)患者血浆内皮素(ET-1)、心钠素(ANP)和降钙素基因相关肽(CGRP)水平的变化.方法:用放射免疫分析方法测定肺心病急性发作期和缓解期患者m浆圈r.1、ANP、CCRP含量,并行同步动脉血气分析.且与慢性阻塞性肺疾病(COPD)组比较.结果:肺心病患者血浆中ET-1和ANP含量升高,CGRP含量降低,尤其以急性期为著.其中ET-1和CGRP的变化不易随病情缓解而恢复,而ET-1的变化与ANP呈显著正相关(r=0.426,P＜0.05),与CGRP和PaO2呈显著负相关(r分别为-0.563、-0.739,P＜0.01).结论:肺心病血中ET-1与ANP、CGRP水平失衡长时间存在,可能是该病病情加重的一个重要体液因素.     

肝硬化患者血浆降钙素基因相关肽和内皮素-1含量分析

目的　观察肝硬化患者血浆降钙素基因相关肽 (CGRP)和内皮素 (ET 1)含量变化。方法　选择肝硬化患者 6 0例 (其中腹水患者 4 3例 )、正常对照 30例 ,用放射免疫法检测其血浆CGRP和ET 1含量。结果　肝硬化组血浆CGRP和ET 1明显高于对照组 (P <0 0 1) ;肝硬化腹水患者高于无腹水患者 (P <0 0 1) ;肝功能Child Pugh分级中C级高于B级、B级高于A级。结论　肝硬化患者血浆CGRP和ET 1水平增高 ,CGRP及ET 1在肝功能损伤及肝硬化高动力循环状态的发生中具有重要作用     

葛根素干预对糖尿病肾病大鼠降钙素基因相关肽的影响研究

目的研究葛根素对糖尿病肾病（DN）大鼠降钙素基因相关肽（CGRP）的影响。方法链脉佐菌素（STZ）诱导糖尿病大鼠模型,随机分为糖尿病组（D组）、葛根素治疗组（S组）,同时另设正常对照组（CN组）,给药干预14周后,测定空腹血糖（FBG）、尿微量白蛋白（U—mAIb）、血浆内皮素（ET）和CGRP含量。结果糖尿病大鼠UAER增加,ET升高,CGRP下降,给予葛根素治疗14周后,S组DN大鼠U—mAIb较D组显著降低,ET显著下降,CGRP明显升高。结论葛根素对糖尿病大鼠肾脏病变有一定的保护作用,其部分机制可能是通过上调CGRP含量而实现的。     

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.     

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.     

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.     

不同程度创伤性脑损伤大鼠降钙素基因相关肽表达变化及其意义

目的建立液压创伤性脑损伤(TBI)模型,探讨创伤性脑损伤大鼠降钙素基因相关肽(CGRP)表达变化及其意义。方法健康雄性Wistar大鼠168只,体质量250～300g,随机分为损伤轻度、中度、重度及对照组各42只。各组分别再随机分为0.5、2、6、12、24、48、72h各7个亚组每组6只。采用液压颅脑损伤仪,对轻度、中度、重度组分别给予0.5～1.0atm(1atm=101.3kPa)、1.5～2.0atm、2.5～3.0atm液压冲击力,制成轻、中、重3型液压颅脑损伤模型。分别于致伤后相应时间点对各组大鼠断头取脑。采用苏木素-伊红(HE)染色观察TBI中组织病理改变,免疫组织化学检测创伤区大脑皮层CGRP表达。结果①光镜观察显示:创伤后12～48h时脑组织损伤最严重。②不同程度TBI中创伤区大脑皮层CGRP神经元表达的阳性单位呈现规律性变化,损伤程度越重,CGRP表达的阳性单位变化幅度越大。不同程度TBI组及对照组之间创伤区大脑皮层中CGRP神经元表达的阳性单位不同,差异有统计学意义;重度组明显低于轻度、中度及对照组,差异有统计学意义;轻度、中度及对照组之间,差异无统计学意义。TBI中损伤程度和时间对于创伤区大脑皮层中CGRP神经元表达的阳性单位有交互效应,中度2h时最高,重度24h时最低。结论不同程度TBI中创伤区大脑皮层CGRP神经元表达的阳性单位量与损伤程度及损伤后时间有关。     

针药结合对急性脑梗死患者血浆降钙素基因相关肽水平的影响

目的 观察针药结合对急性脑梗死患者血浆降钙素基因相关肽(CGRP)水平的影响.方法 90例急性脑梗死患者随机分为针药组(45例)和药物组(45例).两组患者治疗前、治疗后1个月检测血浆CGRP水平及观察临床疗效.结果 针药组总有效率91.1%(41/45)明显高于药物组总有效率77.8%(36/45),差异有统计学意义(P<0.05).治疗后两组血浆CGRP水平较治疗前明显升高(P<0.05),且针药组明显高于药物组(P<0.05).结论 针药结合具有降低急性脑梗死患者的神经细胞损伤作用,且可能与其调节患者CGRP水平有关.     

Involvement of calcitonin gene-related peptide in the depressor effects of losartan and perindopril in rats

Previous investigations have indicated that calcitonin gene-related peptide (CGRP) plays an important role in the regulation of cardiovascular function, and that the development of hypertension may be related to the reduction of sensory vasodilator nerve actions. In the present study, we examined the effect of perindopril, an angiotensin-converting enzyme inhibitor, and losartan, an angiotensin II receptor antagonist, on the plasma level and synthesis of CGRP in 2 kidneys, 1-clip hypertensive rats (2K1C, Goldblatt). In the hypertension group, systolic blood pressure and mean artery pressure were raised, and the level of CGRP in plasma was slightly raised compared with control groups. Chronic treatment with losartan or perindopril significantly increased the plasma concentration of CGRP and the expression of CGRP mRNA in dorsal root ganglia in the 2K1C, Goldblatt hypertensive rats. These results suggest that the 2K1C, Goldblatt hypertensive model has a compensatory increase of sensory nerve actions, and that the depressor effects of perindopril or losartan may be related to stimulation of the synthesis and release of CGRP in the 2K1C, Goldblatt hypertensive rats.     

Modification at Lys24 with fatty acid generates active calcitonin gene-related peptide with much improved plasma stability

As a 37-amino acid vasoactive neuropeptide, calcitonin gene-related peptide (CGRP) is widely distributed in nervous systems. The studies and clinical applications of CGRP are limited by its peptide nature and short half-life. A series of peptide analogues of the α-form of CGRP were synthesized. Afterwards, by using in vitro metabolic and activity studies, we prepared two high affinity analogues with significantly improved plasma stability.     

Evidence for the involvement of calcitonin gene-related peptide in the epithelium-dependent contraction of guinea-pig trachea in response to capsaicin

Summary Capsaicin (10^–9 to 10^–5 M) contracted guinea-pig tracheal strips. Epithelium-containing tracheal strips developed a maximum active tension which was significantly higher than that observed in epithelium-free strips. Anti-CGRP (calcitonin gene-related peptide) serum blocked the epithelium-dependent potentiation of the capsaicin-induced contraction in the intact tracheal strips, without affecting the response of the epithelium-free strips. This result suggests the occurrence of an epithelium-dependent release of CGRP. This same serum markedly reduced the contraction induced by exogenous rat CGRP in both intact and epithelium-free tracheal strips. In epithelium-free tracheal strips, capsaicin-induced contraction was abolished by spantide (10^–6 and 10^–5 M), a substance P antagonist, but, in intact tracheal strips, spantide did not abolish the capsaicin-induced contraction, showing that both CGRP and substance P release are directly induced by capsaicin. Moreover, the contractile responses to rat CGRP of intact tracheal strips from guinea pig suggest that CGRP itself might be able to release a contracting factor from the airway epithelium. Therefore, CGRP originating from the airway epithelium may play a major role in the control of airway smooth muscle tone.Send offprint request to E. Tschirhart at the above address     

降钙素基因相关肽在早期糖尿病肾病中的作用

目的通过检测降钙素基因相关肽(CGRP)在2型糖尿病及早期糖尿病肾病患者血中的含量及其与内生肌酐清除率(Ccr)之间的相关关系,探讨CGRP在糖尿病肾病中的变化及作用。方法选取健康对照组(NC)30名,2型糖尿病组(DM)30例,早期糖尿病肾病组(DN)30例为研究对象,采用放射免疫法测定CGRP,采用方差分析比较各组CGRP水平,采用直线相关分析CGRP与Ccr之间的关系。结果NC组CGRP水平为154.59pg/ml,DM组为249.86pg/ml,DN组为354.78pg/ml。DM组,DN组CGRP水平与NC组比较明显升高,差异有统计学意义(P<0.01)。CGRP与Ccr呈明显负相关(r=-0.52,P<0.01)。结论在糖尿病患者中,随Ccr的下降,CGRP升高,CGRP在糖尿病肾病早期,促进肾脏的高滤过。