一氧化氮合酶阳性神经元在小鼠颈髓的分布

用ＮＡＤＰＨ－ｄ组织化学方法观察小鼠颈髓一氧化氮合酶阳性神经元的分布,结果显示在颈髓的胶状质和中央管周围灰质内有较多一氧化氮合酶神经元分布,在前角基部内侧有较大的ＮＯＳ神经元,这些神经元大多显示Ｇｏｌｇｉ样染色外观,它们尚不能与任何已知的神经递质类型神经元单一对应,后角浅层的中间带分别含有密集和中等密集的ＤＯＳ阳性纤维,一氧化氮合产阳性神经元的纤维较细,有串珠状膨大,相互交织成疏密度不等的网络。     

大鼠端脑神经元型一氧化氮合酶免疫阳性神经元的分布

目的 :观察大鼠端脑神经元型一氧化氮合酶 (nNOS)免疫阳性神经元的分布。方法 :ABC免疫细胞化学法显示大鼠端脑nNOS阳性神经元。结果 :nNOS阳性神经元呈棕褐色 ,胞体的形态多样化 ,呈梭形、三角形、圆形等多种形状 ,突起有一个或多个 ;阳性纤维呈棕色串珠状 ,个别脑区阳性纤维相互交织成网。端脑nNOS免疫阳性神经元主要分布于嗅结节 (包括海马回 )、梨状区 (包括梨状皮质和梨状核 )、斜角带、隔区、杏仁复合体、海马结构、尾壳核和苍白球 ,以及大脑皮质等各个部位 ,其中以大脑皮质、梨状区和斜角带、尾壳核等部位最为丰富。结论 :大鼠端脑内分布有丰富的nNOS阳性神经元 ,它们可能通过调节神经递质的分泌 ,参与脑的高级整合功能。     

大鼠端脑神经元型一氧化氮合酶免疫阳性神经元的分析

目的：观察大鼠端脑神经元一氧化氮合酶（nNOS）免疫阳性神经元的分析。方法：ABC免疫细胞化学显示大鼠端脑nNOS阳性神经元。结果：nNOS阳性神经元呈棕褐色，胞体的形态多样化，呈梭形、三角形、圆形等多种形状，突起一个或多个；阳性纤维呈棕色串珠状，个别脑区阳性纤维相互交织成网。端脑nNOS免疫阳性神经元主要分布于嗅结节（包括海马回）、梨状区（包括梨状皮质和梨状核）、斜角带、隔区、杏仁复合体、海马结构、尾壳核和苍白球，以及大脑皮质等各个部位，其中以大脑皮质、梨状区和斜角带、尾壳核等部分最为丰富。结论：大鼠端脑内分布有丰富的nNOS阳性神经元，它们可能通过调节神经递质的分泌，参与脑的高级整合功能。     

大、小鼠颈髓一氧化氮合酶阳性神经元的分布比较

用NADPH—d组织化学方法观察了大鼠和小鼠颈髓内NOS阳性神经元的分布，结果显示在大、小鼠颈髓的中央管周围灰质内均有较多的NOS阳性神经元分布，大鼠的NOS阳性神经元多集中于中央管背侧，小鼠的分布相对均匀，但以腹侧为多，大、小鼠在后角浅层及胶状质内部均含有密集的NOS阳性神经元，在中间带内侧也均含有较大的中等密集的NOS阳性神经元。大鼠中间带外侧有较多的NOS阳性神经元，而小鼠该处的NOS阳性神经元则少见，结果提示NOS阳性神经元在实验动物颈髓的分布存在种属间差异。     

大鼠海马结构内一氧化氮合酶阳性神经元在学习记…

用还原型烟酰胺腺嘌呤二核苷酸黄递酶组织化学方法，检测空间辩别性学习记忆模型大鼠和对照大鼠的海马结构内一氧化氮合酶（ＮＯＳ）的活性，阳性细胞的分布，形态和数量等形态学指标。结果：（１）模型大鼠海马结构内ＮＯＳ阳性神经元的酶反应产物比对照大鼠的明显减少，（２）模型大鼠和对照大鼠海马结构内ＮＯＳ了性神经元的分布未见组间差异，但均显示出明显的区间差异，即从ＣＡ４区向ＣＡ１区逐渐增眵；（３）模型大鼠和对照大     

小鼠脊髓颈段一氧化氮合酶阳性神经元的分布研究

用NADPH-黄递酶组织化学方法观察小鼠脊髓颈段一氧化氮合酶阳性神经元(Nitric oxide synthase,NOS)的分布,结果显示在颈髓胶状质和中央管周围灰质内有较多一氧化氮合酶神经元分布,在前角基部内侧有较大的NOS神经元.后角浅层和中间带分别含有密集和中度密集的一氧化氮阳性纤维;在颈髓的前索白质和后索白质中也有一氧化氮合酶阳性神经元的分布,NOS阳性神经元的纤维较细,有串珠状膨大,相互交织成疏密不等的网络.这些神经元大多显示Golgi染色外观,它们尚不能与任何已知的神经递质类型神经元单一对应.     

一氧化氮和一氧化氮合酶与脑的几个问题

提出了NO、NOS的脑内分型与表达形式；分析了NO、NOS脑内形态学定位与经典神经递质之间相互关系及其共存方式；总结了NO、NOS脑内神经保护和损伤作用及其与脑循环的调节功能。     

一氧化氮合酶在猕猴中枢神经系统中的表达

研究神经元型一氧化氮合酶(NOS1)在灵长类动物中枢神经系统中的表达．方法：采用免疫组织化学技术，观察了一氧化氮合酶在正常猕猴脑和脊髓中的表达．结果表明NOS1阳性神经元分布于中枢神经系统的广泛区域，包括大脑皮质、海马、齿状回、尾壳核、纹状体、小脑皮质、脊髓前角、后角和中央灰质与中枢神经系统的诸多功能有关．     

大鼠海马结构内一氧化氮合酶阳性神经元在学习记忆时的形态学观察

用还原型烟酰胺腺嘌呤二核苷酸黄递酶（ＮＡＤＰＨ－ｄｉａｐｈｏｒａｓｅ）组织化学方法，检测空间辩别性学习记忆模型大鼠和对照大鼠的海马结构内一氧化氮合酶（ＮＯＳ）的活性，阳性细胞的分布、形态和数量等形态学指标．结果：（１）模型大鼠海马结构内ＮＯＳ阳性神经元的酶反应产物比对照大鼠的明显减少；（２）模型大鼠和对照大鼠海马结构内ＮＯＳ阳性神经元的分布未见组间差异，但均显示出明显的区间差异，即从ＣＡ４区向ＣＡ１区逐渐增多；（３）模型大鼠和对照大鼠海马结构内的ＮＯＳ阳性神经元的数量显示出明显的组间差异，即模型组比对照组的明显减少；（４）模型大鼠和对照大鼠海马结构内的ＮＯＳ阳性神经元形态主要有锥体形、颗粒形和纺锤形三种，但未见组间差异．据此，可认为大鼠海马结构内ＮＯＳ阳性神经元在空间辨别性学习记忆活动时发生了形态学可塑性．它提示一氧化氮可能作为信使参与信息的传递     

一氧化氮合酶在拟黑多刺蚁脑中的分布

一氧化氮作为一种重要的信使分子,参与调节昆虫嗅觉、视觉、机械感受、发育和机体防御.本文采用NADPH-黄递酶组织化学技术,观察了一氧化氮舍酶(NOS)在拟黑多刺蚁脑内的分布,结果表明,NOS在雄蚁和雌蚁的蕈形体、视叶、中央复合体及中脑后脑区均有分布,在工蚁中主要分布在视叶、中脑及后脑区,推测可能对蚂蚁的视觉、嗅觉、记忆及行为产生影响.     

维吾尔族内皮型一氧化氮合酶基因4a/b VNTR多态性分布特征

 应用聚合酶链式反应(PCR)-琼脂糖凝胶电泳技术, 检测99 例(男性38 例, 女性61 例)无血缘关系的维吾尔族健康人群的内皮型-氧化氮合酶(endothelial nitric oxide synthase, eNOS)基因第4 内含子数目可变性串联重复序列(4a/b VNTR)多态性, 探讨eNOS 基因4a/b VNTR 多态性在中国维吾尔族健康人群中的分布特征。结果发现, 99 例健康维吾尔族人群中, aa 基因型频率为2.02%(4 例), ab 基因型频率为22.22%(22 例), bb 基因型频率为75.76%(75 例)。男女两组基因型和等位基因的分布差异不显著(P=0.194, P=0.382, P>0.05)。aa、ab、bb、ab+bb 基因型的各种生理生化指标用单因素方差分析进行比较, 不同基因型的生理生化指标之间的差异无统计学意义(P>0.05)。维吾尔族eNOS 基因4a/b VNTR 多态性与国内外各民族群体进行比较, 维吾尔族人群eNOS 基因aa+ab 基因型频率显著低于河南汉族、中国台湾汉族、北方汉族和巴西黑人(P<0.05, P< 0.01), 明显高于广东汉族(P=0.050)。a、b、c 3 种等位基因进行比较, 维吾尔族与河南汉族、中国台湾汉族、广东汉族、法国人和巴西黑人有显著性差异(P<0.05, P< 0.01)。结果显示, eNOS 基因4a/b VNTR 多态性符合Hardy-Weinbery 遗传平衡规律(χ²=0.017, P=0.991, P>0.05), 群体具有代表性。由此得出, 维吾尔族eNOS 基因4a/b VNTR 多态性与国内外的一些民族间存在显著性差异。     

Temporal hyperacuity in single neurons of electric fish

Behavioural studies have revealed that animals can resolve temporal disparities in the microsecond range. This resolution is far superior to that of individual receptors, and it must therefore be achieved through central neuronal mechanisms. It is unclear, however, whether such sensitivity ever emerges at the level of single neurons, or whether it is apparent only at the behavioural level through the collective action of many less-sensitive neurons. We have found that single neurons in the pre-pacemaker nucleus of a weakly electric fish are sensitive to temporal disparities as small as 1 microsecond, the highest temporal sensitivity ever observed at the single-neuron level. The remarkable temporal resolution of these pre-pacemaker neurons results from a high degree of spatial convergence of afferent inputs. These neurons represent the final elements of a sensory hierarchy and directly control the jamming avoidance response by which these fish regulate the frequency of their electric organ discharges.     

Localization of nitric oxide synthase indicating a neural role for nitric oxide.

Nitric oxide (NO), apparently identical to endothelium-derived relaxing factor in blood vessels, is also formed by cytotoxic macrophages, in adrenal gland and in brain tissue, where it mediates the stimulation by glutamate of cyclic GMP formation in the cerebellum. Stimulation of intestinal or anococcygeal nerves liberates NO, and the resultant muscle relaxation is blocked by arginine derivatives that inhibit NO synthesis. It is, however, unclear whether in brain or intestine, NO released following nerve stimulation is formed in neurons, glia, fibroblasts, muscle or blood cells, all of which occur in proximity to neurons and so could account for effects of nerve stimulation on cGMP and muscle tone. We have now localized NO synthase protein immunohistochemically in the rat using antisera to the purified enzyme. We demonstrate NO synthase in the brain to be exclusively associated with discrete neuronal populations. NO synthase is also concentrated in the neural innervation of the posterior pituitary, in autonomic nerve fibres in the retina, in cell bodies and nerve fibres in the myenteric plexus of the intestine, in adrenal medulla, and in vascular endothelial cells. These prominent neural localizations provide the first conclusive evidence for a strong association of NO with neurons.     

Abnormal expression of inducible nitric oxide synthase in Duchenne muscular dystrophy muscles

Duchenne muscular dystrophy (DMD) is a fatal genetic disease for the youth and children. 8 biopsies of DMD patients were determined and demonstrated that the membrane_binding nitric oxide synthase was enriched in normal skeletal muscles and was little in DMD muscles. The results from Western blot and immunohistochemistry showed that inducible nitric oxide synthase (iNOS) was overexpressed in DMD muscle fibers, while a small amount of highly localized iNOS can be found in normal fibers. Based on these findings, it is proposed that the mechanism of progressive injury in DMD muscle might be associated with the abnormal expression of iNOS.     

Activation of nitric oxide synthase in endothelial cells by Akt-dependent phosphorylation.

Nitric oxide (NO) produced by the endothelial NO synthase (eNOS) is a fundamental determinant of cardiovascular homesotasis: it regulates systemic blood pressure, vascular remodelling and angiogenesis. Physiologically, the most important stimulus for the continuous formation of NO is the viscous drag (shear stress) generated by the streaming blood on the endothelial layer. Although shear-stress-mediated phosphorylation of eNOS is thought to regulate enzyme activity, the mechanism of activation of eNOS is not yet known. Here we demonstrate that the serine/threonine protein kinase Akt/PKB mediates the activation of eNOS, leading to increased NO production. Inhibition of the phosphatidylinositol-3-OH kinase/Akt pathway or mutation of the Akt site on eNOS protein (at serine 1177) attenuates the serine phosphorylation and prevents the activation of eNOS. Mimicking the phosphorylation of Ser 1177 directly enhances enzyme activity and alters the sensitivity of the enzyme to Ca2+, rendering its activity maximal at sub-physiological concentrations of Ca2+. Thus, phosphorylation of eNOS by Akt represents a novel Ca2+-independent regulatory mechanism for activation of eNOS.     

Nitration of a peptide phytotoxin by bacterial nitric oxide synthase

Nitric oxide (NO) is a potent intercellular signal in mammals that mediates key aspects of blood pressure, hormone release, nerve transmission and the immune response of higher organisms. Proteins homologous to full-length mammalian nitric oxide synthases (NOSs) are found in lower multicellular organisms. Recently, genome sequencing has shown that some bacteria contain genes coding for truncated NOS proteins; this is consistent with reports of NOS-like activities in bacterial extracts. Biological functions for bacterial NOSs are unknown, but have been presumed to be analogous to their role in mammals. Here we describe a gene in the plant pathogen Streptomyces turgidiscabies that encodes a NOS homologue, and we reveal its role in nitrating a dipeptide phytotoxin required for plant pathogenicity. High similarity between bacterial NOSs indicates a general function in biosynthetic nitration; thus, bacterial NOSs constitute a new class of enzymes. Here we show that the primary function of Streptomyces NOS is radically different from that of mammalian NOS. Surprisingly, mammalian NO signalling and bacterial biosynthetic nitration share an evolutionary origin.