小鼠下颌下腺NGF基因表达的性别差异研究

实验应用地高辛标记人β神经生长因子ＤＮＡ探针原位杂交组化技术，研究小鼠下颌下腺神经生长因子（ＮＧＦ）表达的性别差异。实验结果显示，雄性和雌性小鼠下颌下腺ＮＧＦ基因表达的部位基本相同，原位杂交反应产物都选择性分布于纹状管和颗粒曲管上皮细胞中，但雄性小鼠原位杂交信号强，雌性小鼠杂交信号较弱，原位杂交阳性小管在雄性小鼠以粗大的颗粒曲管为主，在雌性小鼠以细小的纹状管为主，颗粒曲管较少，而且在单位面积中雄性     

雄激素对发育中小鼠下颌下腺神经生长因子合成的影响

光镜下观察了发育中小鼠下颌下腺内神经生长因子(nerve growth factor,NGF)的免疫反应定位及雄激素对它的影响.在生后发育阶段NGF阳性染色定位于颗粒纡曲导管(granular convoluted tubule,GCT)细胞,并且随着该导管发育的进展而增加;已经证明的成年小鼠下颌下腺NGF表达的性差异在性成熟前已可见到.给发育中小鼠雄性激素促进下颌下腺中GCT的发育和NGF的合成.这些结果表明在小鼠下颌下腺发育过程中雄激素可能对NGF合成起过重要作用.     

生长抑素在小鼠下颌下腺的定位研究

目的：观察生长抑素在成年小鼠下颌下腺的定位和分布。方法；采用免疫组织化学ＡＢＣ方法。结果：小鼠下颌下腺颗粒曲管细胞及副交感神经节内神经元均呈生长抑素免疫反应阳性。结论；生长抑素可能通过激素或神经递质的方式，对下颌下腺复杂的分泌活动起调节作用。     

颌下腺神经内分泌细胞的初步探讨

用NSE-PAP免疫组织化学方法对大鼠、小鼠、猫,猴和人的颌下腺进行了比较观察。在大鼠和小鼠的颌下腺中,阳性反应主要定位于颗粒曲管细胞。纹状管及小叶间导管细胞呈中度阳性反应。猫,猴和人的颌下腺没有颗粒曲管,阳性反应主要定位于纹状管及小叶间导管细胞。对这些NSE阳性细胞的神经内分泌细胞属性进行了讨论。     

FSH受体在大鼠下颌下腺的定位及其与FSH的共存关系

目的研究大鼠下颌下腺FSH受体的定位及其与FSH的免疫共定位关系,证明下颌下腺是FSH的一个靶器官。方法制备大鼠下颌下腺石蜡连续切片以免疫组化SABC法分别研究FSH和FSHR的免疫定位。结果大鼠下颌下腺浆液性腺泡上皮细胞、颗粒曲管、排泄管及分泌管上皮细胞内有FSHR和FSH免疫反应阳性物质共存,阳性物质分布在胞质内,胞核阴性。结论大鼠下颌下腺存在FSHR,是雌激素的靶器官,而且FSHR和FSH共存于下颌下腺相同的细胞,FSH可能通过FSHR的介导调节下颌下腺的功能。     

颌下腺内生物活性物质的研究进展

自从Werle和Roden[1]于1936年在颌下腺中发现激肽释放酶以来,颌下腺的功能便引起了人们的关注。后来,随着神经生长因子(NGF)[2]和表皮生长因子(EGF)[3]相继在颌下腺中被发现,医学上掀起了研究颌下腺内生物活性物质(BAS)的高潮。,几十年来,人们在颌下腺中陆续发现或分离提取出50多种BAS,它们或直接分泌入血,或随唾液进入消化道再由胃肠吸收入血,对多种组织和细胞的生理活动起调节作用。现已证实,啮齿动物颌下腺中的多种BAS主要定位于颗粒曲管(GCT)细胞的分泌颗粒内,而人和其他哺乳动物的颌下腺无GCT细胞,这些物质很可能由纹状管或…     

雌激素受体β在大鼠下颌下腺的免疫组织化学定位

目的：探讨雌激素β型受体（estrogen receptorβ，ER-β）在大鼠下颌下腺的定位和分布，为进一步研究ER-β在下颌下腺的可能功能提供形态学依据。方法：免疫组织化学SABC法。结果：大鼠下颌下腺浆液性腺细胞、泡心细胞、闰管、颗粒曲管及大于颗粒曲管的各级导管上皮细胞均呈ER-β免疫反应阳性，阳性反应物质主要位于阳性细胞胞质内，核呈阴性反应。结论：大鼠下颌下腺存在ER-β，雌激素可能通过ER-β的介导对下颌下腺功能进行调控。     

人胎海马生长抑素和神经生长因子免疫阳性神经元的研究

本文采用免疫细胞化学ABC法对20例胎龄为16～36周的人胎儿海马进行了观察。证明人胎海马存在着生长抑素和神经生长因子免疫阳性神经元，两者均散在分布于海马皮质的深层，为多极神经元；免疫反应阳性颗粒均匀地分布于神经元胞质中，生长抑素阳性细胞中的颗粒比神经生长因子阳性细胞中的颗粒粗大。本文结果提示：人胎海马中存在的上述两类阳性神经元可能在中枢神经系统的发育中起着重要作用。     

大鼠下颌下腺卵泡刺激素及其受体的原位杂交及核心片段的序列分析

目的探讨大鼠下颌下腺组织中是否表达卵泡刺激素(FSH)及其受体(FSHR),为进一步研究FSH对下颌下腺的功能调节提供理论依据。方法正常SD大鼠20只,体质量(200±20)g,腹腔麻醉后切取下颌下腺,采用原位杂交方法对FSH及FSHR进行细胞定位,探讨大鼠下颌下腺是否存在FSH及其受体mRNA,从下颌下腺组织中分别提取总RNA,运用RT-PCR获得FSH及其受体基因的cDNA核心序列,并对其序列进行分析。结果大鼠下颌下腺浆液性腺泡及颗粒曲管上皮细胞含有FSH和FSHR mRNA杂交信号,信号物质分布于胞质内,胞核呈阴性反应。从大鼠下颌下腺组织中扩增的FSH及FSHR基因的特异性条带分别为193bp和413bp。结论大鼠下颌下腺浆液性腺泡及颗粒曲管上皮细胞能合成卵泡刺激素及其受体,进一步说明下颌下腺是FSH作用的靶器官。     

小鼠、大鼠颌下腺颗粒曲管细胞内神经肽的免疫组织化学研究

小鼠、大鼠颌下腺颗粒曲管细胞内神经肽的免疫组织化学研究贾雪梅贾友苏王惠珠齐威琴（安徽医科大学组织学与胚胎学教研室）近年来，人们已从小鼠、大鼠等啮齿类动物的颌下腺中发现或分离出近３０种肽类、蛋白质类及单胺类等生物活性物质，它们主要分布于颗粒曲管（ＧＣＴ...     

Electron microscopical localization of guanylate cyclase activity in the neocortex of the guinea pig

The localization of the guanylate cyclase (GC) activity has been established in the neocortex of adult guinea pigs by means of electron microscopical histochemistry [the DMSO-method of Fujimoto et al. (1981)]. Reaction product was deposited within a population of large- and medium-sized cortical neurons as well as in the cytoplasm of a part of the dendrites of variable size and in the cytoplasm and the nuclear membrane of a number of protoplasmic astrocytes. In the perikarya of the positive neurons, the reaction precipitate was mainly located within the cisterns of the rough endoplasmic reticulum and on the nuclear membrane. In the dendrites, the reaction product was usually distributed in close contact with microtubules, microfilaments, and beneath the postsynaptic membranes of a number of axodendritic synaptic contacts. The axons and all presynaptic boutons were negative. Thus, the localization of the GC could be determined as exclusively postsynaptic. The results obtained support the view for the probable participation of cyclic GMP in the cholinergic, glutaminergic or GABAergic, or peptidergic transmitter mechanisms in the central nervous system.     

Localization of NADPH oxidase subunits in neonatal sympathetic neurons

Reactive oxygen species (ROS) trigger programmed cell death in neonatal sympathetic neurons that have been deprived of nerve growth factor (NGF), however, the source of these oxygen intermediates has not been established. Using laser scanning confocal microscopy (LSCM), the intracellular distribution of the subunits of the ROS-generating enzyme NADPH oxidase was examined in sympathetic neurons of the superior cervical ganglion (SCG). Optical sectioning using LSCM showed that gp91-phox and p22-phox co-localize in neurons at the cell membrane, while the p47-phox and p67-phox subunits are found uniformly distributed in the cytoplasm of neurons maintained in the presence of NGF. Within 4h after NGF deprivation, both the p47-phox and p67-phox subunits exhibit punctate staining in the cytoplasm and at the membrane. Furthermore, a sub-population of the cytosolic p47-phox appeared to co-localize with the membrane-bound gp91-phox in NGF-deprived neurons. These data provide support for the presence of NADPH oxidase in sympathetic neurons and suggest that this enzyme may become activated following the withdrawal of NGF.     

Nerve growth factor decreases potassium currents and alters repetitive firing in rat sympathetic neurons

The sympathetic nervous system is an essential regulator of the cardiovascular system and interactions with target tissue regulate sympathetic neuronal properties. The heart produces nerve growth factor (NGF), which promotes sympathetic noradrenergic innervation of cardiac tissue and affects sympathetic synaptic strength. Neurotrophins, including NGF, are important modulators of synaptic plasticity and membrane electrical properties. Here we show that acute application of NGF causes a change in the repetitive firing pattern of cultured sympathetic neurons of the rat superior cervical ganglion. Neurons fire fewer action potentials in NGF, but with increased frequency, demonstrating an NGF-dependent change from a tonic to a phasic firing pattern. Additionally, NGF decreases the spike time variance, making spikes more tightly time locked to stimulus onset. NGF causes a decrease in the amplitude of both calcium-dependent and -independent potassium currents, and inhibition of calcium-dependent potassium currents using CdCl(2) reproduces some, but not all, of the firing properties induced by NGF. This study suggests that NGF release from cardiac tissue may act to modulate the repetitive firing properties of sympathetic neurons to tune their output to meet the physiological needs of the organism.     

脊髓半横断损伤后腹角神经元神经生长因子、脑源性神经营养因子、神经营养因子-3和神经营养因子-4表达的变化

目的:探讨大鼠脊髓半横断损伤(htSCI)后脑源性神经营养因子(BDNF)、神经生长因子(NGF)、神经营养因子(NT-3、NT-4)在脊髓腹角神经元表达的早期变化。方法:免疫组织化学ABC法分别染4种神经因子并作阳性细胞计数。结果:NGF主要分布于脊髓腹角神经元的胞核,BDNF、NT-4与NT-3主要分布于胞浆。htSCI前后它们在细胞内的分布范围没有变化。BDNF、NGF与NT-3的3 d在损伤尾侧段脊髓双侧腹角阳性神经元数与对照组相比显著减少。BDNF与NGF的14 d的双侧腹角阳性神经元数量均较正常组明显增多,NT-3与NT-4的14 d~21 d的双侧腹角阳性神经元数量均较正常组明显增多,BDNF7~21 d以及NGF14 d的健侧的阳性神经元数量均分别多于相应的伤侧。结论:内源性BDNF、NGF、NT-3、NT-4增加对脊髓损伤修复具有重要作用,BDNF和NGF在健侧表达的增加说明健侧代偿功能的活跃。     

Nerve growth factor in the adult brain of a teleostean model for aging research: Nothobranchius furzeri

Nerve growth factor (NGF) acts on central nervous system neurons, regulating naturally occurring cell death, synaptic connectivity, fiber guidance and dendritic morphology. The dynamically regulated production of NGF beginning in development, extends throughout adult life and aging, exerting numerous roles through a surprising variety of neurons and glial cells.This study analyzes the localization of NGF in the brain of the teleost fish Nothobranchius furzeri, an emerging model for aging research due to its short lifespan. Immunochemical and immunohistochemical experiments were performed by employing an antibody mapping at the N-terminus of the mature chain human origin NGF. Western blot analysis revealed an intense and well defined band of 20 kDa, which corresponds to proNGF of N. furzeri. Immunohistochemistry revealed NGF immunoreactivity (IR) diffused throughout all regions of telencephalon, diencephalon, mesencephalon and rhomboencephalon. It was detected in neurons and in glial cells, the latter mostly lining the mesencephalic and rhomboencephalic ventricles. Particularly in neurons, NGF IR was localized in perikarya and, to a less extent, in fibers.The widespread distribution of proNGF suggests that it might modulate numerous physiological functions in the adult brain of N. furzeri. The present survey constitutes a baseline study to enhance the understanding of the mechanisms underlying the role of NGF during aging processes.     

Localization of NGF and nNOS in varicocele-induced rat testis

Nerve growth factor (NGF) is synthesized in male germ cells. The presence of neuronal nitric oxide synthase (nNOS) in Leydig cells is related to its role in the regulation of testosterone release. Varicocele is often characterized by abnormal sperm quality and influences the fertilizing capacity of the haploid gamete. We investigated the localization of NGF and nNOS in testes of adult Wistar rats with experimentally induced varicocele after 9, 11, and 13 weeks, as well as in sham-operated controls by immunohistochemistry and Western blot. In control testis, we detected NGF in nuclei of Sertoli cells and also as small vesicular-like structures in the cytoplasm of primary spermatocytes, and in round and elongating spermatids. Varicocele-induction revealed a slight decrease of NGF at 13 weeks, especially in Sertoli cells. In control tissue, nNOS protein was present mainly in Leydig cells and in Sertoli cell cytoplasm. Additionally, nNOS immunoreactivity was present in the heads of elongated spermatids. Western blot results revealed that the decrease of NGF was not significant in the13-week varicocele group, moreover, the amount of nNOS was not altered in any of the varicocele groups. In conclusion, NGF and nNOS have important roles for normal gametogenesis and our data for the first time indicates that varicocele induction does not necessarily affect the expression of NGF and nNOS. Thus, these two molecules do not appear to be related to varicocele induction.     

Distribution of nerve growth factor in chick embryo sympathetic neuronsin vitro

Summary The distribution of nerve growth factor (NGF) in chick embryo sympathetic neurons has been followed by two distinct procedures, that is, indirect immunofluorescence microscopy employing purified NGF antibodies and autoradiography after exposure of cells to [^125I]NGF. This study shows that NGF bound to sympathetic neurons is not uniformly distributed but appears in spots over the surface of perikarya and along processes. If the same cells, after incubation with NGF and fixation, are treated with methanol-acetone to allow permeation of immunoglobulins across the plasma membrane, NGF antibody immunoreactive material is also found within the cytoplasm and notably in the paranuclear area only in sympathetic neurons. Analogous findings are obtained when sympathetic neurons are incubated in the presence of [¹²⁵I]NGF, fixed, sectioned and processed for autoradiography. Also with this technique NGF appears to be localized in the cytoplasmic compartment and is found around the nucleus. These studies are discussed in connection with the results of similar experiments performed on a clonal line of NGF target cells known as PC12.     

NGF和bFGF及其受体在金黄地鼠神经管的定位

用免疫组织化学和免疫电镜方法研究了神经生长因子 (NGF)和碱性成纤维细胞因子 (b FGF)及其受体 (Trk A、FGFR)在金黄地鼠神经管发育中的定位分布。结果显示 :NGF和 b FGF的表达时序不同 ,但与各自受体的表达时序基本一致 ,其定位相似。受精后第 8d即出现 b FGF阳性细胞 ,NGF于第 9d出现 ,随着胚龄增加 ,免疫阳性着色逐渐增强 ,二者均定位于神经细胞胞质、神经管内界膜、外界膜 ,脊索和脊神经节细胞胞质中 ,b FGF还分布于神经细胞核。第 8d可检测到少量散在的 FGFR金标颗粒 ,Trk A于第 9d出现 ,随着胚胎的发育 ,金标颗粒逐渐增多 ,主要定位于细胞膜、胞质的基质、内质网、核膜及胞核中。上述结果表明 ,NGF、b FGF及其受体在金黄地鼠胚神经管形成和分化中按着一定的时序出现于细胞的一定部位     

挤压伤后脊髓神经元NGF表达的变化

本研究运用免疫组织化学 ABC法和灰度值测定探讨脊髓挤压伤后 NGF在脊髓腹角和背角神经元表达的早期变化。结果显示 :NGF主要分布于脊髓灰质神经元的胞核及胞浆 ;腹角阳性神经元数量在损伤后 2 1d组较正常组明显增多 (P<0 .0 1) ,而背角的阳性神经元在损伤后 2 4h、7d及 2 1d组均较正常组明显增多 (P<0 .0 1)。腹角和背角神经元的阳性灰度值在挤压伤后各组均较正常组显著降低 (P<0 .0 1)。提示 ,内源性 NGF增加对脊髓损伤修复具有重要作用