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本研究观察了糖皮质激素自身在孤束核NTS内的心血管效应,以及它在NTS内对NA/NPY诱导的心血管活动变化的影响及机制。结果发现,大剂量地塞米松在大鼠NTS的内能很快导致血压下降,血清中NO浓度升高。小剂量Dex在NTS内能很快抑制NA/NPY在NTS内诱导的心血管效应,并维持较长时间。表明Dex对NA/NPY在NTS诱导的心血管效应,并维持较长时间。表明Dex对NA/NPY在NTS诱导的心血管效 相似文献
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为了探讨心内神经节中去甲肾上腺素(NA)、乙酰胆碱(ACh)和NPY的相互作用,本实验应用6-OH-DA选择性切除大鼠心脏交感神经纤维,然后应用荧光和酶组织化学法、免疫组织化学结合图像分析法观察了大鼠心内神经节NA、AChE活性和NPY的变化。结果显示:实验组大鼠心内神经节中儿茶酚胺荧光反应阳性和NPY免疫反应(NPY-IR)阳性的神经纤维明显减少,AChE阳性神经纤维明显增多,AChE反应性神经元积分光密度增加,而儿茶酚胺荧光反应和NPY-IR阳性神经元变化不明显。结果提示:1.交感神经化学切除后大鼠心内神经节中NA、AChE活性和NPY出现不同的变化,体现了心脏交感神经和副交感神经的相互抑制作用;2.心内神经节可能含有两种性质的NPY,即交感性和非交感性NPY。 相似文献
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心脏和肾脏通过一系列神经体液调节机制相互作用,这种作用维持正常状态下的循环稳态.然而,调节机制在充血性心衰时变的异常,充血性心衰患者中,肾功能不全常常会进一步进展.肾交感传出神经激活引起肾素释放,钠水潴留,以及肾血流量减少,都是充血性心衰时肾脏表现.由肾脏部分调节释放的血管紧张素Ⅱ水平增加,作用于中枢神经系统后可增加全身交感神经活性,临床上肾脏交感神经活性可通过去甲肾上腺素分泌进行评估,充血性心衰时去甲肾上腺素分泌增加提示预后不良.除传出交感神经激活外,心衰时肾脏传入神经的激活可反射性引起交感神经活性的增加,进而引起外周血管阻力增加、血管重塑、心室重塑及左室功能障碍.在心衰动物模型中,外科肾脏去交感神经支配术可以改善肾脏和心室功能,但有创性操作过程以及相关并发症限制了其应用.近期出现的经导管射频消融去肾脏交感神经支配术可特异性阻断肾传出、传入神经,已成功应用于顽固性高血压的治疗.目前评估心衰患者肾脏去交感神经支配术安全性及有效性的临床试验正在进行中. 相似文献
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分别向杏仁内侧核(MAN)内微量注射去甲肾上腺素(NA)或神经肽Y(NPY)。NA引起血压升高,心率加快;而NPY引起血压降低,心率减慢。如果注入不能改变血压的小剂量NPY,则可抑制NA引起的升压作用,反映NPY与NA共同参与心血管活动的中枢性调节过程。向MAN中注射NPY后血中NA的含量也相应降低,表明在MAN中注射NPY引起的血压、心率反应是通过降低血浆中NA含量而实现的。 相似文献
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本实验用6-OHDA造成成年小白鼠领下腺化学性去交感神经,观察了神经生长因子对该神经的保护作用。6-OHDA(15mg/kgip)处理后24h腺体内去甲肾上腺素(NE)含量降至正常水平的2%以下。若在6-OHDA处理同时开始多次给予神经生长因子(NGF),则NE残留量明显提高。减小6-OHDA剂量至10mg/kg,NE残留量增加,同时NGF的作用亦较用6-OHDA15mg/kg时更为显著。若提前24h给予NGF,尽管仍显著提高NE残留量,但程度却显然低于与6-OHDA同时给予者。以上结果表明外源性NGF对6-OHDA造成交感神经化学性损毁有保护作用,此作用与神经受损的严重程度以及NGF处理时间有关。 相似文献
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分别向杏仁内侧核(MAN)内微量注射去甲肾上腺素(NA)或神经肽Y(NPY)。NA引起血压长高,心率加快;而NPY引起血压降低,心率减慢。如果注入不能改变血压的小剂量NPY,则可抑制NA引起的升压作用,反映NPY与NA共同参与心血管活动的中枢性调节过程。向MAN中注射NPY后血中NA的含量也相应降低,表明在MAN中注射NPY引起的血压、心率反应是通过降低血浆中NA含量而实现的。 相似文献
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本研究观察了糖皮质激素自身在孤束核(NTS)内的心血管效应,以及它在NTS内对NANPY诱导的心血管活动变化的影响及机制。结果发现,大剂量地塞米松(Dex)在大鼠NTS内能很快导致血压下降,血清中NO浓度升高。小剂量Dex在NTS内能很快抑制NANPY在NTS内诱导的心血管效应,并维持较长时间。表明Dex对NANPY在NTS诱导的心血管效应的抑制作用可能有基因和非基因两种途径参与。进一步分析它的非基因机制发现这种快速抑制作用与胞内糖皮质激素受体无关,而是通过兴奋GABAA受体,降低减压反射;或者降低α2受体的敏感性,抑制NO的形成;或者直接作用于细胞膜上的离子通道以影响它们对NANPY的反应;从而抑制NANPY在NTS内诱导的降压和心率减慢的效应 相似文献
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K. E. Ibrahim M. W. Couch C. M. Williams M. J. Fregly J. M. Midgley 《Journal of neurochemistry》1985,44(6):1862-1867
The development of a radiochemical enzyme assay for p-octopamine in 1969 led to its identification in a large number of invertebrate nerve systems and in mammalian sympathetic nerves. The original method by which p-octopamine was measured has now been found to be nonspecific; however, modifications of this procedure can determine both m- and p-octopamine. We recently developed a new specific method for the unequivocal identification and quantitative determination in tissue of the six octopamine and synephrine isomers. With this method--negative chemical ionization gas chromatography-mass spectrometry--the more physiologically active m-octopamine has been found in association with p-octopamine in 10 organs of the rat. m-Octopamine is present in concentrations equal to those of p-octopamine in heart, spleen, and liver and in concentrations from 30 to 60% of p-octopamine in adrenals, vas deferens, brain, kidney, large intestine, bladder, and lungs. In vivo inhibition of monoamine oxidase markedly increased the concentrations of both m- and p-octopamine in all organs examined. Both amines were virtually absent from all organs except the adrenals following chemical sympathectomy with 6-hydroxydopamine, thereby establishing that m- and p-octopamine are localized within sympathetic nerve endings. 相似文献
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More than 25 years have passed since the original demonstration that proteins such as chromogranin A and dopamine--hydroxylase, which are co-stored together with noradrenaline in large dense cored vesicles in adrenergic nerves, are released by exocytosis. Despite much evidence in favour, it was for a long time thought that large dense cored vesicles were not eminently involved in the release of noradrenaline. The present review attempts to demonstrate, making use of evidence from different approaches, that the release of noradrenaline from sympathetic neurons occurs ultimately from large dense cored vesicles. A model of the secretory cycle is proposed. 相似文献
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Pljesa-Ercegovac M Savic-Radojevic A Kravic-Stevovic T Bumbasirevic V Mimic-Oka J Simic T 《Genetics and molecular biology》2010,33(3):460-462
Transitional cell carcinoma (TCC) of urinary bladder belongs to glutathione S-transferase P1 (GSTP1) overexpressing tumors. Upregulated GSTP1 in TCC is related to apoptosis inhibition. This antiapoptotic effects of GSTP1 might be mediated through protein:protein interaction with c-Jun NH(2) -terminal kinase (JNK). Herein, we analyzed whether a direct link between GSTP1 and JNK exists in TCC. The presence of GSTP1/JNK complexes was analyzed by immunoprecipitation and Western blotting in 20 TCC specimens, obtained after surgery. Co-localization of GSTP1 and JNK was also investigated in the 5637 TCC cell line by immunofluorescence confocal microscopy. By means of immunoprecipitation we show for the first time the presence of GSTP1/JNK complexes in all TCC samples studied. A co-localization of GSTP1 and JNK was also demonstrated in the 5637 TCC cell line by means of confocal microscopy. Protein-protein interactions, together with co-localization between GSTP1 and JNK provide evidence that GSTP1 most probably inhibits apoptosis in TCC cells by non-covalent binding to JNK. 相似文献
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Yucha CB 《Applied psychophysiology and biofeedback》2000,25(1):55-63
Muscle sympathetic nerve activity (MSNA) is an important variable in the study of autonomic activity in both normotensive and hypertensive subjects. It is measured directly from the peroneal nerve using microneurography. The technique is complex and difficult to learn, but yields accurate and direct information about sympathetic nerve impulses. MSNA provides not only greater reproducibility than other measures of sympathetic activity, but also a clearer and more consistent reflection of changes in sympathetic activity caused by changes in the subject's status or disease. This technique has been used primarily in basic research settings studying stress and hypertension. It has much potential to enhance our understanding of sympathetic nervous system activity and its role in applied psychophysiology and biofeedback. 相似文献
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Histamine (HA) was found to be present in the sympathetic nerve terminals of guinea pig hearts and vasa deferentia in our previous study; however, little is known about the functions of this neurogenic HA. In this study, we used guinea pig vasa deferentia to investigate the pre- and post-synaptic functions of HA evoked by different frequencies of sympathetic nerve stimulation. We found that sympathetic nerve stimulation could evoke HA release, which was independent to mast cell degranulator compound 48/80 and mast cell stabilizer cromolyn, but was highly sensitive to Na+ channel blocker tetrodotoxin and chemical sympathectomy with 6-hydroxydopamine. The neurogenically released HA evoked by 12.5 Hz of nerve stimulation activated only pre-synaptic H3 receptors and mediated pre-synaptic inhibitory effects, while under 25 or 50 Hz stimulation condition, HA simultaneously activated both pre-synaptic H3 receptors and post-synaptic H1 receptors. However, the direct contractile responses evoked by sympathetic HA via H1 receptors were observed at 50 Hz. HA release and HA-mediated contractile responses upon sympathetic nerve stimulation were significantly inhibited by pre-treatment of histidine decarboxylase inhibitor α-fluoromethylhistidine. Furthermore, application of exogenous HA could mimic these pre- and post-synaptic effects. Our findings indicate that HA in sympathetic neurons acts as a neurotransmitter and its functions vary from pre-synaptic inhibition, to post-synaptic facilitation, to direct post-synaptic contractile responses according to sympathetic nerve stimulation frequencies. 相似文献
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Cowen T. Jenner C. Song Gu Xiao Santoso A. W. Budi Gavazzi I. 《Neurochemical research》1997,22(8):1003-1011
Whilst the potent effects of NGF and laminin on developing neurons are well documented, relatively little is known about the effects of, or altered availability of or altered responsiveness to, these substances on the growth of adult neurons. We have therefore examined this question using explant cultures of sympathetic neurons from the superior cervical ganglion (SCG) of mature and aged rats. Explants were grown on substrata containing different doses of laminin, either with or without added NGF in culture medium containing FCS. Individually, laminin and NGF had relatively small effects on neurite outgrowth and length, which tended to be reduced in old neurons. In contrast, laminin in the presence of exogenous NGF exerted a powerful effect on nerve growth which was substantially greater than the sum of the effects of the individual factors. This synergy was evident in all experimental groups and was greatest in old explants at high doses of laminin, where growth was comparable to that of mature neurons. The dose-response curve of old neurons to laminin in the presence of added NGF indicated reduced responsiveness. These results suggest that variations in the availability of laminin and/or exogenous NGF, together with altered patterns of neuronal responsiveness, may contribute to impaired neuronal plasticity in old age. 相似文献
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Wohaib Hasan Tetyana Pedchenko Dora Krizsan‐Agbas Laura Baum Peter G. Smith 《Developmental neurobiology》2003,57(1):38-53
Postmitotic sympathetic neuronal survival is dependent upon nerve growth factor (NGF) provided by peripheral targets, and this dependency serves as a central tenet of the neurotrophic hypothesis. In some other systems, NGF has been shown to play an autocrine role, although the pervasiveness and significance of this phenomenon within the nervous system remain unclear. We show here that rat sympathetic neurons synthesize and secrete NGF. NGF mRNA is expressed in nearly half of superior cervical ganglion sympathetic neurons at embryonic day 17, rising to over 90% in the early postnatal period, and declining in the adult. Neuronal immunoreactivity is reduced when retrograde transport is interrupted by axotomy, but persists in a subpopulation of neurons despite diminished mRNA expression, suggesting that intrinsic protein synthesis occurs. Cultured neonatal neurons express NGF mRNA, which is maintained even when they are undergoing apoptosis. To determine which NGF isoforms are secreted, we performed metabolic labeling and immunoprecipitation of NGF‐immunoreactive proteins synthesized by cultured NGF‐dependent and ‐independent neurons. Conditioned medium contained high molecular weight NGF precursor proteins, which varied depending upon the state of NGF dependence. Mature NGF was undetectable by these methods. High molecular weight NGF isoforms were also detected in ganglion homogenates, and persisted at diminished levels following axotomy. We conclude that sympathetic neurons express NGF mRNA, and synthesize and secrete pro‐NGF protein. These findings suggest that a potential NGF‐sympathetic neuron autocrine loop may exist in this prototypic target‐dependent system, but that the secreted forms of this neurotrophin apparently do not support neuronal survival. © 2003 Wiley Periodicals, Inc. J Neurobiol 38–53, 2003 相似文献
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猪流行性腹泻病毒核衣壳蛋白与感染细胞核磷蛋白的共定位分析 总被引:1,自引:0,他引:1
【目的】阐明猪流行性腹泻病毒(PEDV)核衣壳蛋白与病毒感染细胞核仁成分B23.1蛋白的共定位特征。【方法】分别参照GenBank中PEDV CV777株的N基因序列(AF353511)和编码人细胞核仁蛋白B23.1基因序列(BC050628.1),设计、合成扩增N基因和B23.1基因的引物,利用RT-PCR技术扩增了N基因和Vero E6细胞的B23.1基因的cDNA,分别克隆到真核表达载体pAcGFP1-C1和pDsRed2-N1,获得重组质粒pAcGFP1-C1/N和pDsRed2-N1/B23.1,共转染Vero E6细胞。【结果】Western blots分析表明这些融合蛋白在转染的Vero E6细胞中表达;共聚焦显微镜技术分析表明在共转染Vero E6细胞中猪流行性腹泻病毒N蛋白与Vero E6细胞核磷蛋白B23.1发生共定位。【结论】为进一步鉴定PEDV N蛋白中核仁定位信号和N蛋白核仁定位机制提供可靠依据。 相似文献