Calcitonin gene-related peptide inhibits spontaneous contractions in human uterus and fallopian tube

The localization and effects of calcitonin gene-related peptide (CGRP) in the human uterus and fallopian tube were investigated. CGRP-immunoreactive nerve fibers were found in the muscular layers, around blood vessels and close to the epithelium. The oviduct and uterine cervix were more densely innervated than the corpus of the uterus. Substance P (SP)-like immunoreactivity was found in nerves with an overlapping distribution to that of CGRP-positive fibers. CGRP (2 X 10(-10) to 10(-7) M) dose-dependently and reversibly inhibited spontaneous contractions of uterine and oviductal strips, as well as SP-induced contractions in the oviduct. A role for CGRP-containing nerve fibers in regulation of motor activity in human female reproductive organs is suggested.     

Innervation of the feline cerebral vasculature by nerve fibers containing calcitonin gene-related peptide: trigeminal origin and co-existence with substance P

The presence of a population of nerve fibers containing immunoreactive calcitonin gene-related peptide (CGRP) has been demonstrated around cerebral arteries of the cat with immunocytochemistry and radioimmunoassay. CGRP immunoreactivity in the feline cerebral vasculature, as characterized by high-performance liquid chromatography, is similar to authentic rat CGRP. Numerous perikarya containing CGRP are present in the trigeminal ganglia, and surgical lesions of the trigeminal ganglia significantly reduce the levels of CGRP in the cerebral vasculature, suggesting that this cranial nerve is the principal origin of these cerebrovascular nerve fibers. As demonstrated by sequential immunocytochemistry, CGRP coexists with substance P both in the trigeminal ganglion and nerve fibers around cerebral blood vessels. The presence of CGRP in the cerebrovascular trigeminal innervation provides further versatility and complexity for this sensory afferent system putatively involved in the transmission of intracranial pain.     

运动对大鼠冠状血管系统降钙素基因相关肽的影响

目的探讨不同强度运动对降钙素基因相关肽（CGRP）在冠状血管组织中表达的影响及其作用机制。方法健康雄性SD大鼠60只,随机分为对照组、小强度运动组、中等强度运动组和大强度运动组。建立8周不同强度运动训练动物模型,采用免疫组织化学法和计算机图像分析技术对冠状血管组织CGRP的表达进行分析。结果小强度运动组冠状血管组织CGRP表达较对照组变化不明显,中等强度运动组冠状血管组织CGRP表达明显高于对照组（P〈0．05）,大强度运动组冠状血管组织CGRP表达明显低于对照组（P〈0．05）。结论长期中等强度运动使冠状血管组织CGRP分泌增加,改善冠状循环和心肌的血液供应,增强了CGRP对心脏的保护作用。     

Calcitonin gene-related peptide in cardiovascular tissues of the rat

The distribution of calcitonin gene-related peptide immunoreactivity in the cardiovascular system of the rat was investigated by radioimmunoassay and immunocytochemistry. The nature of the immunoreactivity was studied by gel permeation and high performance liquid chromatography. Immunocytochemistry demonstrated the existence of calcitonin gene-related peptide-containing nerve fibres throughout the cardiovascular system. These were present in all regions of the heart, particularly in association with the coronary arteries, within the papillary muscles and within the sinoatrial and atrioventricular nodes. Calcitonin gene-related peptide-containing fibres were found mainly in the adventitia of the arteries and veins. Calcitonin gene-related peptide concentrations were high in major arteries and veins but comparatively low in the heart, aortic arch and thoracic aorta. Chromatography showed that approximately 70% of the total immunoreactivity was identical to synthetic calcitonin gene-related peptide. Calcitonin gene-related peptide concentrations in the blood vessels of rats treated neonatally with capsaicin were not found to be significantly different from those in control animals although capsaicin caused significant reductions of calcitonin gene-related peptide levels in certain other tissues. The results of this study suggest that calcitonin gene-related peptide-containing fibres are likely to be of importance in the innervation of vascular tissues and raise the possibility that these fibres are different in character from calcitonin gene-related peptide-containing fibres found in other tissues.     

降钙素基因相关肽诱导藻酸钙凝胶复合脂肪干细胞的成骨细胞分化

背景：降钙素基因相关肽已被证实具有诱导成骨细胞分化作用,但其是否可使三维培养下的脂肪干细胞向成骨细胞分化构建组织工程骨的相关报道少见。 目的：探讨外源性降钙素基因相关肽诱导兔脂肪干细胞复合藻酸钙凝胶三维培养成骨分化的可行性。 方法：取新西兰兔双侧腹股沟区皮下脂肪垫,Ⅰ型胶原酶消化离心贴壁法分离培养脂肪干细胞,取第3代与海藻酸钠混合制备凝胶,于24孔板分组培养：对照组加入含10^-2 mol/L β-甘油磷酸钠、10^-7 mol/L地塞米松、50 mg/L抗坏血酸、体积分数10%胎牛血清的DMEM/F-12骨诱导培养基,实验组在此基础上再加入1.5 µg/L降钙素基因相关肽进行诱导培养。于诱导不同时间点MTT法检测细胞增殖,RT-PCR法检测诱导细胞Ⅰ型胶原和骨钙素mRNA的表达,并检测碱性磷酸酶及钙离子浓度。 结果与结论：兔脂肪干细胞的增殖曲线呈“S”型,实验组诱导1,3,5,7,14,21 d的A值高于对照组(P < 0.05);诱导2周后两组细胞碱性磷酸酶、茜素红染色均阳性,但实验组钙结节较对照组明显增多。实验组诱导7,14 d的Ⅰ型胶原和骨钙素mRNA表达均强于对照组。实验组诱导1,2,3,4周的碱性磷酸酶活性及钙离子浓度均高于对照组(P< 0.05)。结果表明降钙素基因相关肽能诱导复合藻酸钙凝胶的脂肪干细胞向成骨细胞分化。     

降钙素基因相关肽合成与释放调节

降钙素基因相关肽（calcitonin gene-related peptide, CGRP）是迄今发现的最强的舒血管物质,具有多种重要的生物学作用。作为感觉神经主要递质,CGRP主要由背根神经节合成,某些非神经细胞(如淋巴细胞和内皮细胞)也有表达。CGRP的合成与释放受多种因素调节,除辣椒素受体外,肾上腺素受体、血管紧张素受体、神经生长因子受体和一氧化氮等也参与了CGRP合成与释放的调节。     

大鼠坐骨神经压榨损伤后早期降钙素基因相关肽的变化

目的：研究大鼠坐骨神经压榨损伤后早期降钙素基因相关肽(CGRP)的动态变化及与神经再生的关系。方法：SD大鼠坐骨神经压榨损伤后分别存活1d到21d,免疫组化技术观察CGRP分布和含量的变化。结果：(1)1d组神经CGRP大量堆积,压榨近端明显多于远端,随即下降,21d组基本消失。(2)1d组背根节、脊髓后角和前角CGRP开始增高,并分别在3～5d、5～7d和7d组达峰值,随后渐降,21d组脊髓前角CGRP阳性运动神经元仍明显高于假手术组和对照侧。结论：神经压榨损伤后CGRP表达变化呈明显的时空模式,可能参与了神经元保护并介导了损伤信号的传导。     

CGRP肽能神经在皮肤组织中的分布及其意义

目的:了解降钙素基因相关肽(caleitonin gene-related peptide,CORP)在皮肤组织中的分布、超微定位,以探讨其在皮肤中功能影响.方法:采用ABC-GND免疫组化染色、免疫透射电镜方法观察CGRP在正常皮肤分布和超微结构情况.结果:CGRP分布在表皮下、毛囊、皮脂腺周围、真皮、皮下以及小血管壁周围,其中以小动脉壁阳性纤维密度大.可见粗、细两种纤维,前者位于真皮深层及皮下,后者位于表皮下、毛囊皮脂腺周围.四肢较胸背皮肤CGRP分布相对多而明显.结论:CGRP可能作为神经调节或神经递质参与皮肤各种生理功能调节.尤其在血管周围分布,可能作为CGRP调节皮肤的机制研究和可能的药物治疗的研究基础.     

Detection of calcitonin and calcitonin gene-related peptide mRNA in human medullary thyroid carcinoma. A retrospective study

In Situ hybridization finds many applications in modern pathology. In many cases, special attention is paid to the processing of the tissues prior to in situ hybridization. In order to investigate the value of RNA in situ hybridization (RISH) in retrospective studies, we performed RISH for calcitonin and calcitonin gene-related peptide (CGRP)-I and HomRNA in eight medullary thyroid carcinomas processed in 1981–1983. RISH was successful with radioactive calcitonin and CGRP-1 probes. With biotinylated probes, only calcitcnin-specific probes gave adequate results. The concentrations of CGRP mRNA were probably too low to be detected by non-radioactive RISH. The results of RISH were correlated with the immunohistochemical localization of the polypeptides. The results matched in all cases except one, where hybridization for calcitonin mRNA was found, but no immunoreactive calcitonin polypeptide. We con-clude that RISH can be successfully used for retrospective analysis, even after long storage of tissue embedded in poraffin.     

肾血管性高血压时脑与肠系膜动脉壁CGRP能神经纤维分布的变化

目的：观察肾血管性高血压时中枢与外周动脉壁CGRP（calcitonin gene-related peptide）能神经纤维分布的变化,探讨CGRP与肾血管性高血压的关系.方法：应用免疫组织化学SABC法观察双肾双夹肾血管性高血压大鼠不同时期（术后4、8、12周）脑动脉壁和肠系膜动脉壁CGRP能神经纤维密度的变化.结果：高血压各组CGRP能神经纤维密度均高于对照组,有显著性差异（P＜0.01）;高血压组12周CGRP能神经纤维密度高于高血压组4周,有显著性差异（P＜0.01）;对照组CGRP能神经纤维较纤细,多沿血管长轴走行,高血压组CGRP能神经纤维较粗大,呈网状分布.结论：随着血压的升高,中枢与外周动脉壁CGRP能神经纤维密度增加,这可能是机体产生的一种代偿性保护机制,起着调节血压的作用.     

Topographic localization of calcitonin gene-related peptide in the rat brain: an immunohistochemical analysis

The distribution of immunoreactive calcitonin gene-related peptide in the rat brain was investigated by means of an indirect immunofluorescence method. In addition to previously reported calcitonin gene-related peptide-like immunoreactive structure-containing sites such as the nucleus ambiguus, nucleus originis nervi facialis, nucleus originis nervi hypoglossi, nucleus peripeduncularis and nucleus parabrachialis, the present study demonstrated a far wider distribution of calcitonin gene-related peptide-like immunoreactive structure-containing cells in the rat brain, i.e. the nucleus hypothalamicus lateralis, nucleus ventromedialis thalami, colliculus superior, lemniscus lateralis, gyrus dentatus, nucleus olivaris superior, nucleus tractus solitarii, nucleus cuneiformis, nucleus parabigeminalis and a proportion of the Purkinje cells. We have also demonstrated a more extensive network of calcitonin gene-related peptide-like immunoreactive fibers distributed in various areas throughout the rat brain than has been reported previously such as the colliculus inferior, nucleus olivaris superior, nucleus vestibularis lateralis and inferioris, and nucleus cochlearis dorsalis and ventralis, etc.     

Pregnancy and sex steroid hormones enhance circulating calcitonin gene-related peptide concentrations in rats

Calcitonin-gene-related peptide (CGRP) is a 37 amino acid neuropeptide synthesized primarily in dorsal root ganglia (DRG) and distributed widely in the perivascular nerves, suggesting that this peptide may play a role in the regulation of peripheral vascular tone. Since female sex steroid hormones have been implicated in the regulation of peripheral vascular tone during pregnancy, we postulated that they may alter the concentration of CGRP in the circulation and thus modulate the increased blood flow observed during pregnancy. In the present study, we measured changes in plasma concentrations of CGRP in non-pregnant, pregnant, and post-partum rats. Groups of ovariectomized rats were treated s.c. for 3 days either with 17beta-oestradiol (2.5 microg per injection twice daily), progesterone (2 mg per injection twice daily), or vehicle. Another group of adult, non-pregnant rats at dioestrus stage of the oestrous cycle was also used in this study. Plasma concentrations of CGRP were higher (P < 0.05) in rats on day 19 of pregnancy (22.0 +/- 3.0 pmol/l) compared to that during delivery (5. 0 +/- 2.0), post-partum day 2 (2.0 +/- 0.7) or in non-pregnant (4.9 +/- 1.6) state. Furthermore, in adult ovariectomized (6.0 +/- 0.6) rats, plasma CGRP concentrations were increased significantly (P < 0. 05) by oestradiol (10.0 +/- 1.0), progesterone (9.5 +/- 1.0) and oestradiol + progesterone (14.0 +/- 1.0). Thus, circulating concentrations of CGRP are elevated during pregnancy and by oestrogen and progesterone, suggesting that the elevated concentrations of CGRP may play an important role in vascular adaptations that occur during pregnancy.     

Developmental studies on vasoactive intestinal peptide,substance P and calcitonin gene-related peptide in salivary glands of postnatal rats

The development of vasoactive intestinal peptide, substance P and calcitonin gene-related peptide in parotid, submandibular and sublingual glands of the male rat was followed by immunochemistry and immunocytochemistry. The total amounts of these peptides increased in surges during the first 8 weeks of the animal's life; one within 2–4 weeks and the other beginning 1–2 weeks later. Nerve fibres containing these peptides were present at birth showing a pattern of distribution similar to that in adults. During the first 4 weeks the nerve fibres increased in number.     

Regional differences in the noradrenergic and cholinergic innervation of the pial arteries of the brain

Considerable regional differences in the noradrenergic innervation of the pial arteries of rats were found histochemically (by the condensation reaction with glyoxal). The distal portions of the arteries (arterial bordering zones) were not innervated or were much less richly innervated then the proximal portions (the zones of supply of the individual vessles_. Fibers detected by the reaction for acetylcholinesterase were more uniformly distributed. It is suggested that insufficiency of the noradrenergic innervation may be one factor responsible for the lower resistance of vessels of the arterial bordering zones to an acute rise of arterial pressure.Laboratory of Experimental Pathology of the Nervous System, Research Institute of Neurology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR E. V. Shmidt.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 2, pp. 141–143, February, 1980.     

降钙素基因相关肽对大鼠胃平滑肌的调控作用

目的:探讨降钙素基因相关肽(CGRP)对大鼠胃平滑肌的调控作用。方法:贴块法原代培养大鼠胃平滑肌细胞,特异性平滑肌肌动蛋白α-actin免疫细胞化学鉴定。实验分CGRPⅠ组(10~(-7)mol/LCGRP)、CGRPⅡ组(10~(-8)mol/L CGRP)、CGRPⅢ组(10~(-9)mol/L CGRP)和干预组(10~(-6)mol/LCGRP 8-37)与空白对照组。图像分析系统测定大鼠胃平滑肌细胞长度;Ca~(2+)荧光指示剂测定细胞内Ca~(2+)浓度;CellTiter-Glo~试剂盒检测细胞内ATP含量。结果:CGRP可舒张胃平滑肌细胞,降低胃平滑肌细胞游离Ca~(2+)浓度及ATP含量。结论:CGRP通过受体介导直接参与胃平滑肌细胞松弛;CGRP可能通过降低胃平滑肌细胞游离Ca~(2+)浓度、ATP含量而发挥其调控作用。     

Expression of calcitonin gene-related peptide receptor components,calcitonin receptor-like receptor and receptor activity modifying protein 1, in the rat placenta during pregnancy and their cellular localization

Calcitonin gene-related peptide (CGRP), one of the most potent endogenous vasodilators known, has been implicated in vascular adaptations and placental function during pregnancy. The present study was aimed to investigate mRNA expression of CGRP-A receptor components, calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein 1 (RAMP(1)) in the rat placenta. Immunohistochemical staining of rat placentas obtained on day 18 of pregnancy using polyclonal anti-CRLR and RAMP(1) antibodies revealed that labelling was specifically concentrated in the cytotrophoblast and syncytium in labyrinth, trophoblastic giant cells and basophilic cells in trophospongial cell layer, and endothelium and smooth muscle cells in fetal vessels. The intensity of staining was reduced in all these cells except in the syncytium in placentas obtained during labour. RT-PCR analysis showed that mRNA expression of CRLR and RAMP(1) was significantly higher in the rat placenta from gestation day 17 to day 22, than during labour. During pregnancy, 17beta-estradiol inhibits, while progesterone stimulates, placental mRNA and proteins for CRLR and RAMP(1). Antiestrogen, ICI 182780, increased, whereas antiprogesterone, RU 486, inhibited the expression of both CRLR and RAMP(1). In summary, we demonstrate the presence and cellular localization of CRLR and RAMP(1) in the rat placenta. Elevated placental CRLR and RAMP(1) may be involved in CGRP-related increases in blood flow and therefore fetal growth and decreases at term labour may help minimize the blood loss.     

Airway expression of calcitonin gene-related peptide in T-cell peptide-induced late asthmatic reactions in atopics

BACKGROUND: The mechanisms of late asthmatic reactions provoked in atopic asthmatics by allergen-derived T-cell peptide epitopes remain unclear. Previous studies showed no changes in airway eosinophils or mast cell products after peptide challenge. In the present study our aim was to measure calcitonin gene-related peptide (CGRP), neurokinin (NK)-A, and substance P (SP) in bronchoalveolar lavage fluid and bronchial biopsies (BB) after inhalation of allergen-derived T-cell peptide epitopes since these neuropeptides (NP) had not previously been evaluated in this chronic asthma model. METHODS: Bronchoscopy, with BB and bronchoalveolar lavage (BAL), was performed in 24 cat-allergic subjects 6 h after inhalation of Fel d 1-derived peptides. Neuropeptides were measured in BAL by enzyme-linked immunosorbent assay and CGRP expression in the airways was assessed by immunohistochemistry and confocal microscopy. RESULTS: Twelve subjects (termed 'responders') developed isolated late reactions. Calcitonin gene-related peptide, but not NK-A or SP, was significantly elevated in BAL in responders only. Biopsy studies showed that in virtually all responders peptide challenge induced marked increases in CGRP immunoreactivity in bronchial epithelial cells, infiltrating submucosal cells and in association with airway smooth muscle. Double immunostaining indicated that CGRP colocalized predominantly to CD3+/CD4+ and CD68+ submucosal inflammatory cells. CONCLUSION: Calcitonin gene-related peptide, a potent vasodilator, is markedly up-regulated in the airways of atopic asthmatics during late-phase reactions provoked by inhalation of allergen-derived T-cell peptides.     

Effects of calcitonin gene-related peptide on membrane currents in mammalian cardiac myocytes

We examined the effects of calcitonin gene-related peptide (CGRP) on the membrane currents of single atrial and ventricular cells of guinea pig heart. The tightseal whole-cell voltage-clamp technique was used. In atrial cells, like isoproterenol, CGRP increased the L-type Ca channel current (I _Ca.L) in a concentration-dependent manner. Human CGRP-(8-37), a putative CGRP receptor antagonist, completely abolished the CGRP-induced increase of I _Ca.L. Although the effects of CRGP were similar to those of isoproterenol, propranolol, a -adrenergic receptor antagonist, did not affect the CGRP-induced increase of I _Ca.L. After I _Ca.L had been maximally activated by isoproterenol (2 M) or intracellular cyclic adenosine 5-monophosphate (100 M), CGRP failed to increase I _Ca.L. Acetylcholine antagonized the effects of CGRP on I _Ca.L. Unlike the effects on atrial cells, CGRP had no significant effects on the membrane currents of ventricular myocytes. Thes results indicate that CGRP increases I _Ca.L via adenylate cyclase activation by binding to specific membrane receptors in cardiac atrial myocytes. Furthermore, CGRP receptors are expressed in atrial cells but probably not in ventricular cells.