毛细支气管炎患儿血浆CGRP、VIP RIA的意义

目的：通过愉洲毛细支气管炎患儿急性期和恢复期血浆中降钙素基因相关肽（CCRP）、血管活性肠肽（VIP）的含量,探讨毛细支气管炎患儿血浆CGRP、VIP放射免疫分析（RIA）的意义。方法：本文采用放射免疫分析测定了31例毛细支气管炎患儿急性期和恢复期血浆CGRP、VIP的浓度,以35例正常婴幼儿血浆CGRP、VIP的浓度为对照。结果：毛细支气管炎患儿急性期血浆CGRP浓度明显高于恢复期及正常对照组婴幼儿（P〈0．05）;恢复期CGRP浓度有所下降,但仍高于正常对照组（P〈0．05）,三组间有显著差异（F=82．50,P〈0．01）;毛细支气管炎患儿急性期血浆VIP浓度明显低于恢复期及正常对照组婴幼儿（P〈0．05）;恢复期V1P浓度有所升高,但仍低于正常对照组（P〈0．05）;三组之间有显著性差异（F=300．20,P〈0．01）。结论：CGRP、VIP定量分析结果表明毛细支气管炎患儿血浆CGRP、VIP含量与病程紧密相关。CGRP、VIPRIA对于小儿毛细支气管炎发病机制的研究以及了解其发病病程和指导治疗有着重要的意义。     

扬子鳄泄殖腔壁内血管活性肠肽的分布

目的：观察含血管活性肠肽（VIP）神经在爬行类动物－扬子鳄泄殖腔壁内的分布特点。方法：免疫组织化学ABC法及免疫荧光法。结果：扬子鳄泄殖腔壁内VIP免疫反应阳性神经纤维见于粘膜下层及肌层,呈串珠状,大致与平滑肌纤维平行走行,并见其分支在实质内构成网络状,但明显伴血管走行的纤维稀少。通过免疫荧光法证实,粘膜下层内存在VIP免疫反应阳性细胞,胞体大小、形态不一。结论：扬子鳄泄殖腔已具备了类似高等脊椎动物的含VIP神经的调节。     

外源性FGF—2对损伤面运动神经元降钙基因相关肽表达的影响

目的：研究外源性成纤维细胞生长因子－2(fibroblast growth factor,FGF-2）对损伤面运动神经元降钙基因相关肽（calcitonin gene-related peptide,CGRP）代谢的调节作用。方法：采用大鼠面神经损伤模型，在损伤面神经近侧断端国外源性FGF－2，同时以生理盐水做对照，观察面运动神经元CGRP免疫阳性细胞数和灰度值。结果：与生理盐水组比较，FGF－21组和FGF－2Ⅱ组损伤侧面运动神经元CGRP染色强度明显下降（灰度值百分比：P＜0．01）；FGF－2Ⅱ组损伤侧面运动神经元CGRP阳性细胞数减少（阳性细胞数比；P＜0．05）。结论：外源性FGF－2对损伤面运动神经元CGRP的表达有负向调节作用。     

μ阿片受体在大鼠结肠肠肌丛的神经化学特性

目的:探索μ阿片受体(MOR)在大鼠结肠肠肌丛的分布及化学神经解剖学特性。方法:取大鼠结肠右曲和左曲之间肠管行全层铺片,剥离粘膜层、粘膜下层和环形肌层,保留纵行肌层。运用免疫荧光组织化学双重标记技术染色,共聚焦显微镜下观察MOR在大鼠结肠肠肌丛的分布及与一氧化氮合酶(NOS)、肠血管活血肽(VIP)、P物质(SP)或降钙素基因相关蛋白(CGRP)等在肠神经细胞的共存关系。结果:免疫荧光组织化学染色显示:在大鼠结肠肠肌层,MOR阳性细胞聚集形成神经节,其阳性突起穿行于神经节之间形成网格状神经丛。在肠肌丛神经细胞内,可见MOR分别与NOS、VIP、SP、CGRP共存。MOR阳性神经纤维和终末分布于NOS阳性神经细胞周围,也可见部分NOS、VIP阳性神经纤维和终末分布于MOR阳性神经细胞表面。有大量SP和CGRP阳性神经纤维穿行于MOR阳性神经细胞之间并包绕于MOR阳性神经细胞的胞体周围。结论:在结肠的肠肌丛,MOR与抑制性和感觉性神经递质在肠神经细胞有共存,且相互之间有纤维联系,推测MOR可能介导了阿片类调节肠神经细胞内抑制性神经递质的释放,并可能对肠感觉信息的传递有调节作用。     

大鼠下丘脑内前阿黑皮素原mRNA的老年变化

研究大鼠下丘脑内前阿黑皮素原（POMC）mRNA表达的老年变化，本实验采用SPraque－Dawley大鼠3月龄（青年组）和28～30月龄（老年组）各8只，利用地高辛标记POMC反义RNA探针进行原位杂交组织化学并行图象定量分析。结果：在青年组大鼠肉，OPMCmRNA阳性胞体主要分布于弓状核及其邻近区域；老年大鼠POMCmRNA胞体主要分布于弓状核的内侧，着色浅谈．与年轻大鼠相比，老年大鼠下丘脑内POMCmRNA神经元数量显著减少，（P＜0．01），胞体灰度值明显升高（P＜0．05），而胞体截面积略有增大，但差异无显著性（P＞0．05）。结果表明，大鼠下丘脑内POMCInRNA神经元有明显的老年变化，提示老年大鼠下丘脑POMC神经元胞体发生了衰老形态学改变，功能活动低下，细胞丢失，POMC的表达显著增加，生物合成功能紊乱。     

猪食管神经支配的神经化学研究——一氧化氮类及肽类成分在平滑肌中的分布(英文)

采用免疫荧光组织化学技术及迷走神经切断术,探讨猪食管一氧化氮类及肽类神经支配的神经化学特性。在光学显微镜下可观察到肌间神经丛及粘膜下神经丛中有部分神经元呈nNOS、VIP、GAL、NPY、PACAP、L-ENK、SP、5-HT及CB免疫阳性,但未见CGRP及SOM阳性神经元。nNOS及CB免疫阳性产物主要分布于不同的神经元胞体内。将PGP9.5作为神经元胞体的标记物,并采用免疫荧光免疫组织化学双重染色方法,分别观察了PGP9.5与nNOS、VIP、SP的双标情况。结果如下:(1)nNOS免疫阳性神经元约占PGP9.5标记神经元总数的63%,而VIP免疫阳性神经元约占36%,SP免疫阳性神经元约占28%;(2)神经节内神经元的平均数量呈现吻尾方向的递增趋势,且食管腹段神经丛内神经节数量明显高于食管其他部位;(3)食管肌层内VIP/GAL/NPY免疫阳性纤维分布最广,其中部分阳性纤维同时呈nNOS或PACAP免疫阳性;SP和/或L-ENK免疫阳性纤维在粘膜肌层的分布明显多于平滑肌层。CGRP阳性纤维非常少见,这一点不同于对其他动物的观察结果;(4)经一侧迷走神经切断后,肌间神经丛内PACAP及5-HT免疫阳性纤维明显减少,提示这些纤维可能来源于迷走神经;而平滑肌中VIP/GAL/NPY和/或nNOS免疫阳性纤维数量未发现明显变化,可能为内源性来源。     

大鼠肠缺血/再灌注损伤时血浆ET、CGRP水平的变化及PLA_2阻断剂的影响

Wistar大鼠肠缺血／再灌注损伤后，血浆ET、CGRP水平明显升高（P＜0．05，P＜0．01）。PLA2阻断剂氯喹、消炎痛、三氟拉嗪于缺血／再灌注损伤前应用可明显延长损伤大鼠的存活时间，减轻肠缺血／再灌注时远端脏器肺组织的损伤，同时降低血浆ET、明显升高血浆CGRP水平。上述结果提示：ET、CGRP参与缺血／再灌注损伤过程。PLA2阻断剂可抑制损伤时ET释放，并通过某些环节促进机体释放CGRP，这可能是它们在此条件下，对机体保护作用的机制之一。     

P物质、血管活性肠肽和乙酰胆碱能神经在大鼠肠道内的分布及其关系

应用乙酰胆碱酯酶(AChE)组织化学和PAP免疫组织化学方法,比较观察P物质(SP)、血管活性肠肽(VIP)和AChE三种阳性神经元在大鼠十二指肠、空肠、回肠、结肠和直肠内的分布特征及其相互关系。结果显示:SP、VIP、AChE阳性神经神经元和纤维均分布于肠壁各层,从十二指肠、空肠到回肠逐渐增多,但从结肠到直肠则逐渐减少;AChE阳性神经元或纤维在肠壁各层最丰富,其中VIP以粘膜层和粘膜下神经丛较丰富,SP以肠肌丛较丰富;三者的分布密度为AChE>VIP>SP。AChE、SP和VIP阳性神经元胞体及神经纤维在不同肠段的分布密度有明显差异(P<0.05),提示可能与不同肠段肠动力调节功能有关。     

肠神经系统脑肠肽神经元的免疫组化研究

近年来 ,应用免疫组织化学方法发现胃肠壁内的肠神经系统 (entericnervoussystem ,ENS)可以合成和释放许多种脑肠肽 ,但是与控制胃肠运动有关的脑肠肽是否存在于ENS尚不清楚。我们已报道在灌流大鼠离体胃给以兴奋性脑肠肽胃动素和胃泌素可增强其收缩 ,而用抑制性脑肠肽血管活性肠肽 (vasoactiveintestinalpolypeptides,VIP)则引起其舒张[1 ] 。本研究旨在用免疫组化方法观察胃壁ENS是否有胃动素、胃泌素及VIP神经元存在 ,及这些脑肠肽神经元与ENS网络及Cajal细胞的关系 ,这对阐明脑肠肽对胃肠运动的调控有重要意义。1　材料和方法1 …     

类风湿性关节炎患者血浆中ET和CGRP的变化及意义

目的 探讨内皮素（ET）及降钙素基因相关肽（CGRP）在类风湿性关节炎（RA）发生、发展过程中的作用。方法 采用放射免疫分析法,对30例RA患者及20例正常对照组血浆中ET及CGRP的水平进行检测。结果 RA患者血浆中ET的水平及ET／CGRP的比值明显升高,CGRP水平明显降低,与正常对照组相比较差异显著（P＜0．01）。进一步分析表明,活动期RA患者及关节X线改变为Ⅲ－Ⅳ期的RA患者,血浆ET的水平及ET／ GGRP的比值明显高于稳定期关节改变为I－Ⅱ期的RA患者;而血浆CGRP的水平明显低于后者（P＜0．01）。结论 RA患者体内存在明显地ET及CGRP的平衡失调,且与RA患者的病情严重程度密切相关,提示ET及CGRP参与了RA的发病过程。     

Multiple neuropeptides in nerves supplying mammalian lymph nodes: messenger candidates for sensory and autonomic neuroimmunomodulation?

By the use of light microscopic (LM) immunohistochemistry, the presence of peptides and of dopamine beta-hydroxylase (DBH) in nerves supplying mammalian (guinea pig, rat, cat, pig, mouse, human) lymph nodes were examined. In all species, lymph nodes of various somatic and visceral regions were found to contain nerve fibers which stained for neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), substance P (SP), calcitonin gene-related peptide (CGRP) or DBH. SP- and CGRP-immunoreactive (ir) fibers completely overlapped and exhibited the widest distribution. They were present in perivascular, paravascular and many non-vascular fibers travelling in close contact with lymphoid cells. In contrast, NPY-ir fibers coincided with those staining for DBH, prevailed in perivascular plexus and only rarely branched off into lymphoid parenchyma. Alternate staining of adjacent sections revealed that SP/CGRP-ir fibers were different from NPY/DBH-ir fibers. The distribution of VIP-ir fibers was identical to that of PHI-ir fibers and partially overlapped with that of ir-NPY/DBH or ir-SP/CGRP fibers. We conclude that the NPY innervation of lymph nodes is sympathetic noradrenergic while nerves coding for co-existing SP and CGRP are most likely of sensory origin. The nerves containing co-existing VIP and PHI may be of heterogenous origin (sensory, cholinergic sympathetic, and/or parasympathetic). We suggest that these distinct sensory and autonomic peptidergic pathways linking the nervous system with the lymph nodes may play a differential role in bidirectional neuroimmunomodulation.     

Peripheral amplification of sweating – a role for calcitonin gene-related peptide

Neuropeptides are the mediators of neurogenic inflammation. Some pain disorders, e.g. complex regional pain syndromes, are characterized by increased neurogenic inflammation and by exaggerated sudomotor function. The aim of this study was to explore whether neuropeptides have a peripheral effect on human sweating. We investigated the effects of different concentrations of calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and substance P (SP) on acetylcholine-induced axon reflex sweating in healthy subjects (total n = 18). All substances were applied via dermal microdialysis. The experiments were done in a parallel setting: ACh alone and ACh combined with CGRP, VIP or SP in various concentrations were applied. Acetylcholine (10⁻² m ) always elicited a sweating response, neuropeptides alone did not. However, CGRP significantly enhanced ACh-induced sweating ( P < 0.01). Post hoc tests revealed that CGRP in physiological concentrations of 10⁻⁷–10⁻⁹ m was most effective. VIP at any concentration had no significant effect on axon reflex sweating. The duration of the sweating response ( P < 0.01), but not the amount of sweat, was reduced by SP. ACh-induced skin blood flow was significantly increased by CGRP ( P < 0.01), but unaltered by VIP and SP. The results indicate that CGRP amplifies axon reflex sweating in human skin.     

Distribution of CGRP, substance P, VIP and somatostatin immunoreactive nerve fibers in the internal gills of larvae of the bullfrog, Rana catesbeiana.

CGRP, substance P (SP), VIP and somatostatin were demonstrated in the internal gills of larval bullfrogs using the immunohistochemical peroxidase-antiperoxidase method. Three groups of immunoreactive fibers were distinguished by their distribution area. The first group includes CGRP, SP and VIP immunoreactive fibers running in the connective tissue of the gill tufts. These fibers were associated with the capillaries. Some CGRP fibers were distributed similarly to SP fibers, and the density of VIP immunoreactive fibers was low. The second group includes CGRP, SP, VIP and somatostatin fibers distributed in the connective tissue surrounding the ceratobranchialia. The third group includes CGRP, SP and somatostatin fibers located in the branchial muscle. Their terminals appeared to be neuromuscular junctions. No immunoreactivity of leu- or met-enkephalins was found in the internal gills. From these findings, the first group of fibers is presumed to be involved in modulating ion transport of the internal gills. The second group of fibers except for the somatostatin fibers is thought to be continuations of the first group of fibers. The third group of fibers may possibly be involved in the modulation of transmissions at the neuromuscular junction. It is unclear whether somatostatin terminals are also involved in this.     

Cutaneous innervation of the human face as assessed by skin biopsy

The morphology of cutaneous sensory and autonomic innervation in human trigeminal territory is still unknown. The aim of this study is to describe facial cutaneous innervation using skin biopsy. This new tool could be useful in understanding the mechanisms underlying several facial pain conditions. In 30 healthy subjects, we quantified epidermal nerve fibers (ENFs) and dermal myelinated fibers (MFs) in V1, V2 and V3, using indirect immunofluorescence and confocal microscopy applied to 2‐mm punch skin biopsies from areas adjacent to the eyebrow, upper and lower lip. Using selective markers, we also evaluated the distribution of peptidergic, cholinergic and noradrenergic fibers. Facial skin appeared abundantly innervated and rich in annexes. The ENF density decreased and the MF density increased, moving from the supraorbital to the perioral skin. Noradrenergic sudomotor fibers were particularly and constantly expressed compared with other body sites. Distribution of vasoactive intestinal peptide‐immunoreactive (VIP‐ir) fibers appeared peculiar for their constant presence in the subepidermal neural plexus – in close contact, but without colocalization with calcitonin gene related peptide (CGRP) and substance P (Sub‐P)‐ir fibers. Finally, in perioral skin samples, we observed striated muscle fibers with their motor nerves and motor endplates. Our work provides the first morphological study of human facial cutaneous innervation, highlighting some unique features of this territory. Quantification of unmyelinated and myelinated fibers on 2‐mm punch biopsies appeared to be feasible and reliable. Facial skin biopsy may be a new approach with which to study and to better characterize facial pain syndromes.     

Immunocytochemical analysis of potential neurotransmitters present in the myenteric plexus and muscular layers of the corpus of the guinea pig stomach

Recent electrophysiological studies of neurons of the myenteric plexus of the corpus of the guinea pig stomach have revealed that slow synaptic events are extremely rare. In contrast, they are commonly encountered in similar investigations of myenteric ganglia of the guinea pig small intestine. The current immunocytochemical analysis of the myenteric plexus and innervation of the muscularis externa of the corpus of the guinea pig stomach was undertaken in order to determine whether putative neurotransmitters capable of mediating slow synaptic events are present in gastric ganglia. A major difference between the small intestine and the stomach was found in the innervation of the musculature. Whereas the longitudinal muscle layer of the small intestine contains very few nerve fibers and is innervated mainly at its interface with the myenteric plexus, the longitudinal muscle of the corpus of the stomach contained as many varicose substance P (SP)-, vasocative intestinal polypeptide (VIP)-, and neuropeptide Y (NPY)-immunoreactive axons as the circular muscle layer. These putative neurotransmitters were also present in the ganglia of the myenteric plexus, where varicose SP-, VIP-, and NPY-immunoreactive fibers encircled nonimmunoreactive neurons. Varicose 5-hydroxytryptamine (5-HT)-immunoreactive terminal axons were essentially limited to the myenteric plexus and were found both in ganglia and in interganglionic connectives, where they were particularly numerous; 5-HT-immunoreactive neurons appeared to be more abundant in the stomach than in the small intestine. Tyrosine hydroxylase (TH)- and calcitonin-gene-related-peptide (CGRP)-immunoreactive axons were also more common in the myenteric plexus than in the musculature, but of these, only the TH-immunoreactive neurites tended, like those of the other putative transmitters, to encircle neurons in myenteric ganglia. Evidence was obtained that, as in the small intestine, at least some of the SP-, VIP-, NPY-, and 5-HT-immunoreactive fibers in the stomach are derived from intrinsic gastric myenteric neurons. In contrast, unlike the small intestine, gastric myenteric ganglia appeared to lack intrinsic CGRP-immunoreactive neurons; therefore, the CGRP-immunoreactive gastric axons are probably of extrinsic origin.(ABSTRACT TRUNCATED AT 400 WORDS)     

A型肉毒毒素降低大鼠胃平滑肌收缩及P物质含量

目的：在胃窦前壁注射A型肉毒毒素( BTX-A)后观察局部P物质（substance P）含量和分布的变化及其胃平滑肌收缩的变化，揭示两者之间的关系。 方法： 健康Wistar大鼠30只（普通级），体重260-300 g，雌雄不限。随机分为BTX-A组（B group）及对照组(A group)，在胃体前壁与幽门部交界线中点平滑肌内分别注射0.3 mL BTX-A (20 U/kg)，或0.9 % 氯化钠溶液0.3 mL； 记录胃肌电24 min后，切取局部胃前壁组织行放射免疫测定和免疫组化。结果： ① 放射免疫检测结果提示胃前壁组织中BTX-A组SP平均含量较对照组低28%（P＜0.01），免疫组化结果显示BTX-A组SP免疫反应阳性产物含量较对照组低11%（P＜0.05）；②注射BTX-A 12 min，24 min后， BTX-A组胃肌电的各项指标除24 min后峰电位发生率无显著差异(P＞0.05)外，其它均低于对照组（P＜0.05）。结论： BTX-A可以减少局部SP的含量，这种减少导致了胃肠平滑肌收缩功能的抑制。     

Decreased distribution of nitric oxide synthase and vasoactive intestinal polypeptide positive nerve cells in the sphincter of Oddi in humans with pancreatobiliary diseases

To better understand the relationship between innervation in the sphincter of Oddi and pancreatobiliary diseases, nerve cells which possess nitric oxide synthase (NOS) and/or vasoactive intestinal polypeptide (VIP) were studied immunohistochemically in the sphincter of Oddi and duodenum of humans. Specimens from autopsies included 11 cases with pancreatobiliary diseases and 7 cases without such diseases. An elaborate nerve network was revealed with an anti-S-100 antibody in the sphincter of Oddi and duodenum of all specimens. In the sphincter of Oddi of the control group, approximately 47% of the myenteric nerve cells were NOS positive, whereas 54% were VIP positive. Of the NOS positive nerve cells, 21% were also VIP positive. In contrast, 11% of the nerve cells in the sphincter of Oddi of the disease group were NOS positive while 32% were VIP positive. Within the duodenal myenteric plexus of the control group, 35% of all nerve cells were NOS positive while 40% was VIP positive; among them, 23% of the NOS positive cells were VIP positive. Similar results were observed in the duodenum of the disease group. These data indicate that abundant NOS and VIP positive innervation is present in the sphincter of Oddi and duodenum in humans. The lower proportion of NOS positive or VIP positive nerve cells of the disease group may suggest an inadequacy of the sphincter of Oddi to relax.     

Nerve plexuses in the trachea and extrapulmonary bronchi of the rat

Intrinsic nerve plexuses of the rat trachea and extrapulmonary bronchi were examined by immunohistochemistry. Three nerve plexuses--peritracheal and peribronchial, intramuscular, and submucosal--were found in the wall of the trachea and bronchi. Nerve cell bodies were located in the peritracheal and peribronchial nerve plexuses. They occurred singly or formed ganglia in the plexus, and regional differences in cell numbers were found in the cervical and thoracic portions of the trachea and in the extrapulmonary bronchia. In total, 83.5 +/- 28.3 ganglia (mean +/- SD, 57-131, n=5) and 749.8 +/- 221.1 nerve cell bodies (540-1,080, n=5) were found in the nerve plexus. The mean densities of ganglia were 0.31, 0.97 and 1.15/mm2, and the mean densities of the nerve cell bodies were 1.82, 9.26 and 11.54/mm2 in the cervical region, thoracic region of trachea, and extrapulmonary bronchi, respectively. Almost all nerve cell bodies in ganglia were positive for choline acetyltransferase and neuropeptide Y (NPY), and a few cells were positive for vasoactive intestinal peptide (VIP). In addition, in cholinergic nerves, a few nerve fibers in the smooth muscles were positive for substance P (SP), calcitonin gene-related peptide (CGRP), and VIP, and a moderate number of fibers were positive for NPY. Tyrosine hydroxylase-immunoreactive nerve fibers were observed around blood vessels and within nerve bundles in the tunica adventitia. In the epithelium, nerve fibers were positive for SP and CGRP. Our results indicate that postganglionic neurons form three layers of cholinergic plexuses in the rat trachea and extrapulmonary bronchi, and that all of these possess intrinsic and extrinsic peptidergic innervation.     

Neurovascular plasticity in the knee joint of an arthritic mouse model

Lower numbers of neuropeptide-containing fibers in arthritic joints have been found as compared to control joints. This may be the result of fiber depletion, necrosis of fibers, or proliferation of soft tissues without neural sprouting. To discriminate between these possibilities, we studied the relationships between soft tissue proliferation, changes in vascularity of synovial tissues, and changes in joint innervation during arthritis. Arthritis was induced in the knee joint of mice by a single subpatellar injection of methylated bovine serum albumin after previous immunization. Antibodies to protein gene product 9.5, S-100, and growth-associated protein-43 (GAP-43) were used to study the general innervation pattern. Antibodies to calcitonin gene-related peptide (CGRP), vasointestinal polypeptide (VIP), substance P (SP), and tyrosine hydroxylase (TH) were used to localize sensory (SP, CGRP, VIP) and sympathetic (TH) fibers. Blood vessels of the joint were studied with ink perfusion, GAP-43, and a vascular marker (LF1). Directly after the induction of arthritis, the synovial cavity was enlarged and filled with leukocytes. From day 4 onward, small sprouting blood vessels penetrated the avascular mass of cells in the joint cavity. After 1 week, the vascular sprouting activity and GAP-43 immunoreactivity were maximal, and after 2 weeks, vascular sprouting activity diminished. In the subsequent period, the synovia slowly regained their prearthritic appearance and thickness. The most pronounced changes in the general staining pattern of CGRP, SP, VIP, and TH were found in the periosteum. From 2 days to 4 weeks after the induction of arthritis, the layer of SP, CGRP, and VIP fibers in the femoral periosteum was thicker and more irregular. GAP-43 staining showed many terminal varicosities, which suggested sprouting of nerve fibers. From 2 days to 2 weeks after the induction of arthritis, the SP and CGRP fibers in the periosteum showed gradual depletion. In the thickened subsynovial tissues that were revascularized, no ingrowth of neural elements was found. As the total number of nerve fibers in the synovial tissue did not change, large parts of the synovia directly facing the joint cavity were not innervated at 1 week after the induction of arthritis. These results strongly suggest that periosteal SP and CGRP fibers were depleted during arthritis. Synovial proliferation without concomitant fiber growth is the main cause of the reduced number of immunocytochemically detectable fibers in the mouse arthritic knee joint.     

Calcitonin gene-related peptide-immunoreactive nerve fibers in mandibular periosteum of rat: evidence for primary afferent origin

Peptidergic neurons may play a role in the local regulation of bone mineralization. The neuropeptide vasoactive intestinal peptide (VIP) increases bone resorption in vitro, while calcitonin gene-related peptide (CGRP) has been shown to inhibit bone resorption in vitro. We have previously reported that sympathetic nerves with VIP-immunoreactivity innervate bone and periosteum. In the present study we sought to determine if CGRP fibers, like VIP fibers, exist in periosteum and what their origin might be. In whole-mount preparations of mandibular periosteum from rat, CGRP- and VIP-immunoreactive (IR) nerve fibers were present as networks within the periosteum. In preparations using two-color immunofluorescence, most CGRP-IR fibers were also immunoreactive for substance P (SP). In rats in which the subperiosteal space subjacent to the mandibular molars was injected with Fast blue or Fluoro-gold, retrogradely labeled cells were seen in ipsilateral trigeminal ganglia, superior cervical ganglia, and nodose ganglia. Individual cells labeled with both CGRP immunoreactivity and retrograde tracer were seen only in the mandibular portion of the trigeminal ganglion. These data suggest that CGRP-IR nerve fibers in periosteum may be of primary afferent origin. Given the reported effects of CGRP on bone mineralization, the present results suggest that primary afferent nerves containing CGRP and SP, as well as sympathetic nerves containing VIP, may play a role in focal bone remodeling.