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1.
蛋白磷酸酶降低参与阿尔茨海默病(AD)神经元退化,本旨在探讨一氧化氮(NO)在tau蛋白过度磷酸化引起AD脑神经元退化中的可能作用。采用β-还原型尼克酰胺腺嘌呤二核苷酸磷酸-黄递酶(β-NADPH-d)组织化学技术研究不同剂量蛋白磷酸酶抑制剂岗田酸(OA)对嗜铬细胞瘤细胞株(PC12)一氧化氮合成酶(NOS)活性的影响。结果显示1nmol/LOA与PC12共培养48小时,NOS活性轻度增强;当增加OA浓度至10nmol/L时,培养24和48小时均可见NOS活性明显增强,结果表明根据1nmol/LOA抑制蛋白磷酸酶(PP)-2A,而10nmol/LOA除完全抑制PP-2A外,还部分抑制PP-1,提示PP-2A和PP-1的抑制均可增强NOS活性使NO产生增加,关于蛋白磷酸酶活性降低和NO产生增多与AD的关系和作用有待继续研究。  相似文献   

2.
Enzyme histochemistry and immunocytochemistry were used to determine the distribution of neurons in the snail Helix aspersa which exhibited nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase activity and/or immunoreactivity to nitric oxide synthase (NOS). NADPH diaphorase-positive cells and fibres were distributed extensively throughout the central and peripheral nervous system. NADPH diaphorase-positive fibres were present in all neuropil regions of the central and peripheral ganglia, in the major interganglionic connectives and in peripheral nerve roots. NADPH diaphorase-positive cell bodies were found consistently in the eyes, the lips, the tentacular ganglia and the procerebral lobes of the cerebral ganglia; staining of cell bodies elsewhere in the nervous system was capricious. The distribution of NOS-like immunoreactivity differed markedly from that of NADPH diaphorase activity. Small clusters of cells which exhibited NOS-like immunoreactivity were present in the cerebral and pedal ganglia; fibres which exhibited NOS-like immunoreactivity were present in restricted regions of the neuropil of the central ganglia. The disjunct distributions of NADPH diaphorase activity and NOS-like immunoreactivity in the neurvous system of Helix suggest that the properties of neuronal NOS in molluscs may differ sigificantly from those described previously for vertebrate animals.  相似文献   

3.
The presence of Ca(2+)-dependent, heat-stress-activated nitric oxide synthase (NOS) activity in peculiarly shaped, fusiform, and dendritic sponge cells is described for the first time. The NOS activity was evidenced evaluating the conversion of radioactive citrulline from [(14)C]arginine in intact cells from two different species that are phylogenetically unrelated in the class of Demospongiae: Axinella polypoides and Petrosia ficiformis. The production of nitrogen monoxide (NO) was confirmed by electron paramagnetic resonance analysis, and the histochemistry technique of NADPH diaphorase showed a specific localization of NOS activity in a particular network of dendritic cells in the sponge parenchyma. Sponges are the most primitive metazoan group; their evolution dates back 600 million years. The presence of environmental stress-activated NOS activity in these organisms may prove to be the most ancient NO-dependent signaling network in the animal kingdom.  相似文献   

4.
 The presence of NADPH diaphorase staining was compared with the immunohistochemical localization of four NADPH-dependent enzymes – neuronal (type I), inducible (type II), and endothelial (type III) nitric oxide synthase (NOS) and cytochrome P450 reductase. Cell types that were immunoreactive for the NADPH-dependent enzymes were also stained for NADPH diaphorase, suggesting that endothelial and neuronal NOS and cytochrome P450 reductase all show NADPH diaphorase activity in formaldehyde-fixed tissue. However, in some tissues, the presence of NADPH diaphorase staining did not coincide with the presence of any of the NADPH-dependent enzymes we examined. In vascular endothelial cells, the punctate pattern of staining observed with NADPH diaphorase histochemistry was identical to that seen following immunohistochemistry using antibodies to endothelial NOS. In enteric and pancreatic neurons and in skeletal muscle, the presence of NADPH diaphorase staining correlated with the presence of neuronal NOS. In the liver, sebaceous glands of the skin, ciliated epithelium, and a subpopulation of the cells in the subserosal glands of the trachea, zona glomerulosa of the adrenal cortex, and epithelial cells of the lacrimal and salivary glands, the presence of NADPH diaphorase staining coincided with the presence of cytochrome P450 reductase immunoreactivity. In epithelial cells of the renal tubules and zona fasciculata and zona reticularis of the adrenal cortex, NADPH diaphorase staining was observed that did not coincide with the presence of any of the enzymes. Inducible NOS was not observed in any tissue. Thus, while tissues that demonstrate immunoreactivity for neuronal and endothelial NOS also stain positively for NADPH diaphorase activity, the presence of NADPH diaphorase staining does not reliably or specifically indicate the presence of one or more NOS isoforms. Accepted: 2 September 1996  相似文献   

5.
本文采用辣根过氧化物酶(HRP)逆行追踪技术结合硫辛酰胺脱氨酸(NADPH-d)组织化学方法,研究正常豚鼠耳蜗核一氧化氮合酶(NOS)阳性神经元的上行投射特点。探讨耳蜗核NOS阳性神经元在听觉信号传递中的可能作用。结果表明,一侧上橄榄复合体加压注射HRP后,两侧耳蜗核均出现HRP标记细胞,同侧耳蜗核NOS-HRP双标细胞较多占82.63%,并可见HRP阳性纤维和终末包绕NOS阳性胞体,对侧耳蜗核NOS-HRP双标细胞相对较少,仅占14.87%。一侧下丘加压注入HRP后两侧耳蜗核均无HRP-NOS双标细胞。结果提示,耳蜗核NOS阳性神经元向上橄榄复合体投射,可能具有调节听觉声信号传递的作用  相似文献   

6.
The localization of nitric oxide synthase (NOS) in vascular endothelial cells of submucosal blood vessels from the guinea-pig ileum was examined using NADPH diaphorase histochemistry at the light microscopic level, and endothelial NOS immunohistochemistry at the light and electron microscopic level. The pattern of staining observed following NADPH diaphorase histochemistry and endothelial NOS immunohistochemistry was identical. Endothelial cells of the arterioles, capillaries and venules showed small patches of intense, perinuclear staining. Under the electron microscope, endothelial NOS immunoreactivity was found predominantly in association with the Golgi apparatus and with the membranes of some vesicles. Small regions of the plasma membrane and the rough endoplasmic reticulum also showed some immunoreactivity. The presence of NOS in the Golgi apparatus and in vesicles raises the possibility that NOS may be exteriorized by endothelial cells, and hence that nitric oxide is synthesized extracellularly.  相似文献   

7.
用还原型辅酶Ⅱ黄递酶组织化学和一氧化氮合酶(NOS)免疫细胞化学技术研究了成年爪蛙(Xenopuslaevis)鼻粘膜NOS的阳性结构。嗅上皮中嗅感觉神经元和支持细胞,以及固有层中的神经束、血管和粘膜下腺均呈还原型辅酶Ⅱ黄递酶阳性染色。在嗅上皮中,未见Ⅰ型或Ⅱ型NOS抗体免疫反应阳性结构,但鼻内侧窦和内侧窦口顶嗅上皮中的嗅感觉神经元见有Ⅲ型NOS强免疫反应。在固有层中,Ⅰ型或Ⅲ型NOS免疫反应性存在于神经束和血管中,未见于粘膜下腺的腺泡中。结果表明,不同异型的NOS存在于爪蛙鼻粘膜中,提示一氧化氮可能参与爪蛙的化学感觉活动。  相似文献   

8.
We colocalized nitric oxide synthase (NOS) activity in epithelial cells that surround the salivary gland duct in female Dermacentor variabilis with NADPH diaphorase histochemistry and immunohistochemistry using a polyclonal anti-endothelial NOS. Using size-exclusion chromatography, a fraction with a molecular mass of about 185 kDa that had diaphorase activity was eluted from tick salivary gland homogenate. This fraction converted arginine to citrulline with the production of nitric oxide (NO), which was detected by using electron spin resonance spectroscopy. The complete activity of the diaphorase fraction was dependent on NADPH, FAD, tetrahydrobiopterin, calmodulin, (CaM), and Ca(2+), but was not dependent on dithiothreitol. The arginine analog N(G)-monomethyl-L-arginine inhibited the activity of this fraction. NO and arginine activated soluble guanylate cyclase to produce cGMP in dopamine-stimulated isolated salivary glands. Dopamine-stimulated isolated salivary glands treated with tick saline containing either EDTA, the NOS inhibitor N(G)-nitro-L-arginine methyl ester, or the calcium/CaM binding inhibitor W-7 showed no increase in cGMP. The NO donor sodium nitroprusside significantly increased cGMP levels in unstimulated isolated salivary glands. A possible function for NO in salivation by this ixodid tick is discussed.  相似文献   

9.
目的:研究丹参注射液(SM)对庆大霉素(GM)耳中毒豚鼠耳蜗血管纹一氧化氮合酶(NOS)活性的影响及其与听阈的关系,探讨SM对GM耳毒性损伤的保护作用。方法:应用NADPH-黄递酶(NADPH-d)组织化学染色以及图象分析技术,并结合听性脑干反应(ABR)测试。结果:SM-GM组耳蜗血管纹NOS活性和ABR阈值均明显低于GM组(P<0.01);且各组NOS活性变化与ABR阈移高庆相关(rcontrol=-0.9464;rGM=-0.9117;rSM GM=-0.8958,P<0.01)。结论:SM可通过降低耳蜗血管纹NOS活性以减轻GM的耳毒性损伤,从而改善听功能。  相似文献   

10.
目前已知下丘脑是应激反应的关键性调节中枢,下丘脑内一氧化氮是否参与应激反应尚未见报道。本文运用NADPH-d酶组化技术和计算机图象分析方法,对束缚应激大鼠下丘脑室旁核(PVN)和视上核(SON)一氧化氮合酶(NOS)阳性神经元的相对切面面积和平均灰度进行了分析。结果显示,大鼠在急性束缚应激4小时后,其下丘脑PVN和SON内的NOS阳性神经元的平均灰度值与正常大鼠比较均明显降低(P<0.001);SON的NOS阳性神经元的相对切面面积明显大于正常大鼠(P<0.001),但PVN的NOS阳性神经元的相对切面面积未见明显改变(P>0.05)。以上结果说明束缚应激使大鼠下丘脑PVN和SON的NOS活性增强  相似文献   

11.
Nitric oxide synthase I (NOS I) has been localized to the skeletal muscle sarcolemma in a variety of vertebrate species including man. It is particularly enriched at neuromuscular junctions. Recently, the N-methyl-d-aspartate (NMDA) receptor subunit 1 (NMDAR-1) has been detected in the postjunctional sarcolemma of rat diaphragm, providing a clue as to the possible source of Ca2+ ions that are necessary for NOS I activation. To address this possibility, we studied the distribution of NMDAR-1 and NOS I in mouse and rat skeletal muscles by immunohistochemistry and enzyme histochemistry. NMDAR-1 and NOS I were closely associated at neuromuscular junctions primarily of type II muscle fibers. NOS I was also present in the extrajunctional sarcolemma of this fiber type. Dystrophin, β-dystroglycan, α-sarcoglycan, and spectrin were found normally expressed in both the junctional and extrajunctional sarcolemma of both fiber types. By contrast, in the muscle sarcolemma of MDX mice, dystrophin and dystrophin-associated proteins were reduced or absent. NOS I immunoreactivity was lost from the extrajunctional sarcolemma and barely detectable in the junctional sarcolemma. NOS I activity was clearly demonstrable in the junctional sarcolemma by NADPH diaphorase histochemistry, especially when the two-step method was used. NMDAR-1 was not altered. These data suggest that different mechanisms act to attach NOS I to the junctional versus extrajunctional sarcolemma. It may further be postulated that NMDA receptors are involved not only in the regulation but also sarcolemmal targeting of NOS I at neuromuscular junctions of type II fibers. The evidence that glutamate may function as a messenger molecule at vertebrate neuromuscular junction is discussed.  相似文献   

12.
Neuronal nitric oxide synthase (NOS), an enzyme capable of synthesizing nitric oxide, appears to be identical to neuronal NADPH diaphorase. The correlation was examined between NOS immunoreactivity and NADPH diaphorase staining in neurons of the ileum and colon of the guinea-pig. There was a one-to-one correlation between NOS immunoreactivity and NADPH diaphorase staining in all neurons examined; even the relative staining intensities obtained were similar with each technique. To determine whether pharmacological methods could be employed to demonstrate that NADPH diaphorase staining was due to the presence of NOS, tissue was pre-treated with NG-nitro-L-arginine, a NOS inhibitor, or L-arginine, a natural substrate of NOS. In these experiments on unfixed tissue, it was necessary to use dimethyl thiazolyl tetrazolium instead of nitroblue tetrazolium as the substrate for the NADPH diaphorase histochemical reaction. Neither treatment caused a significant decrease in the level of NADPH diaphorase staining, implying that arginine and NADPH interact at different sites on the enzyme.  相似文献   

13.
Summary Neuronal nitric oxide synthase (NOS), an enzyme capable of synthesizing nitric oxide, appears to be identical to neuronal NADPH diaphorase. The correlation was examined between NOS immunoreactivity and NADPH diaphorase staining in neurons of the ileum and colon of the guinea-pig. There was a one-to-one correlation between NOS immunoreactivity and NADPH diaphorase staining in all neurons examined; even the relative staining intensities obtained were similar with each technique. To determine whether pharmacological methods could be employed to demonstrate that NADPH diaphorase staining was due to the presence of NOS, tissue was pre-treated with NG-nitro-l-arginine, a NOS inhibitor, or l-arginine, a natural substrate of NOS. In these experiments on unfixed tissue, it was necessary to use dimethyl thiazolyl tetrazolium instead of nitroblue tetrazolium as the substrate for the NADPH diaphorase histochemical reaction. Neither treatment caused a significant decrease in the level of NADPH diaphorase staining, implying that arginine and NADPH interact at different sites on the enzyme.  相似文献   

14.
J Weiske  A Wiesner 《Nitric oxide》1999,3(2):123-131
In contrast to the vertebrate immune system, nearly nothing is known about the immunological role of nitric oxide (NO) in invertebrates. This study provides evidence of the presence of a NO synthase (NOS) activity in an immune-competent, macrophage-like insect hemocyte line, previously established from larvae of the lepidopteran insect Estigmene acraea. As proven by photometric determination of nitroblue tetrazolium reduction after cell fixation, the E. acraea cells possess NADPH diaphorase (NADPHd) activity. This NADPH diaphorase activity was NADPH dependent, not inhibitable by superoxide dismutase, influenced by extracellular addition of L-arginine, and inhibited in a dose-dependent manner by the specific NOS inhibitor Nomega-monomethyl-L-arginine. Furthermore, the NADPH diaphorase activity was stimulated within 30 min by the addition of insect pathogenic bacteria (Bacillus thuringiensis var. kurstaki, Photorhabdus luminescens), bacterial lipopolysaccharide, and silica beads. In activated E. acraea cell suspensions strongly increased amounts of L-citrulline and enhanced levels of total nitrite/nitrate (as NO derivates) can be determined. This is the first report on stimulable NOS activity in insect hemocytes.  相似文献   

15.
大白鼠中缝核一氧化氮合酶阳性神经元的组织化学观察   总被引:2,自引:1,他引:1  
中脑和脑桥部中缝核被认为与睡眠有直接和间接关系的重要脑结构。本文用一氧化氮合酶(NOS)组织化学结合荧光组织化学方法证实在中缝核群中,NOS阳性神经元主要定位于这两个脑部的中缝核内,NOS产生的NO能使脑血管扩张,参与脑血流的调节。提示这二个脑部中缝核内的NOS阳性神经元可能作为多种因素之一,参于睡眠状态下基本脑血流的维持  相似文献   

16.
17.
Yu KL  Tamada Y  Suwa F  Fang YR  Tang CS 《Life sciences》2006,78(10):1143-1148
Many histochemical investigations indicated that the oxytocin (OXY), the arginine vasopressin (AVP) and the nitric oxide synthase (NOS) have been synthesized in the supraoptic nucleus (SON) neurons. The objective of this study was to examine the age-related expression of the OXY, the AVP and the NOS in the SON of the young adult (2-month-old) and the aged (24-month-old) rats. The histochemistry for reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d; marker for the NOS) and the double labeling histochemistry for the OXY/NADPH-d or the AVP/NADPH-d were employed, and the quantitative analysis was performed with a computer-assisted image processing system. In comparison of the young adult and the aged group, the cell number, the cell size and the reactive density of the NOS-expressing neurons showed a significant increase along with age, and these evidences suggested the age-related increase of the nitric oxide (NO) production. The age-related significant increase was not detected in the number of the OXY/NOS-expressing neurons in the dorsal part, but was detected in the number of the AVP/NOS-expressing neurons in the ventral part. Based on our histochemical findings and reports demonstrated by other authors, we attempted to discuss the physiological role of NOS for the secretion of posterior pituitary hormones along with age.  相似文献   

18.
Nitric oxide (NO) has been shown to play an important role in both the neuroendocrine reproductive and stress axes, which are closely linked. Because progesterone (P4) receptors (PRs) and glucocorticoid receptors (GRs) are not found in GnRH neurons and the NOergic system has been implicated in the control of GnRH secretion, this study aimed to ascertain whether steroids altered the NOergic system. Our first objective was to map the distribution of NO synthase (NOS) cells in the ovine preoptic area (POA) and hypothalamus and to determine whether NOS activity is enhanced by estradiol (E2) treatment. Using NADPH diaphorase (NADPHd) histochemistry, we found that NADPHd-positive neurons were spread throughout the ovine POA and hypothalamus, and that all NADPHd cells were immunoreactive for NOS. In response to estradiol, a significant increase in the number of NADPHd cells was noted only in the ventrolateral region of the ventromedial nucleus (VMNvl), with no significant difference in the POA or arcuate nucleus. Progesterone and glucocorticoid receptors were colocalized with NADPHd reactive neurons in the POA, arcuate nucleus, and VMNvl of ewes in both treatment groups. In ewes receiving estradiol, the number of NADPHd-positive cells containing steroid receptors in the POA (PR, 81%; GR, 79%) and arcuate nucleus (PR, 89%; GR, 84%) was similar, but in the VMNvl, fewer NADPHd-positive cells contained GR (PR, 88%, GR, 31%). These data show that estradiol up-regulates NOS activity in a site-specific manner and that the influence and possible interaction of progesterone and corticosteroids on NO producing cells may differ according to the neural location.  相似文献   

19.
目的 观察扬子鳄新皮质内一氧化氮合酶(nitric oxide synthase,NOS)和乙酰胆碱酯酶(acetylcholinesterase,AChE)阳性神经元的形态和分布,为扬子鳄脑的比较解剖学积累资料,为其机能研究提供形态学依据.方法 采用还原型尼克酰胺腺嘌呤二核苷酸黄递酶(NADPH-d)法和亚铁氰化酮法观察扬子鳄新皮质内NOS和AChE阳性神经元的分布和特征.结果 扬子鳄新皮质内有NOS和AChE阳性神经元分布,为大、中、小型细胞,以中小型细胞为主,胞体呈圆形、椭圆形、三角形和梭形.结论 扬子鳄新皮质内有NOS和AChE阳性神经元分布.  相似文献   

20.
一氧化氮合酶在豚鼠听觉核团的分布   总被引:4,自引:0,他引:4  
为了研究一氧化氮合酶(nitricoxidesythase,NOS)在听觉核团的分布特点,探讨一氧化氮(nitricoxede,NO)在听觉径路中的作用,本文采用NADPH硫辛酸胺脱氢酶(NADPH-d)组织化学方法,研究了豚鼠听觉核团内NOS的分布。结果发现,在各级听觉传入核团,均有NOS阳性神经元,而上橄榄复合体NOS反应阴性。耳蜗核NOS阳性神经元主要集中在耳蜗后腹核,为圆形或椭圆形双极神经元。下丘NOS阳性反应神经元位于下丘中央核团,胞体形状和大小不一。内侧膝状体背侧核NOS阳性神经元相对集中,多为双极神经元,部分神经元突起很长,散在阳性纤维,部分阳性纤维穿行于内侧膝状体背侧核与内侧膝状体之间。本研究提示,NO可能是听觉中枢的神经递质或调质,参与声信号传递的调节。  相似文献   

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