Identification and localization of cell types that express endothelial and neuronal nitric oxide synthase in the rat nucleus tractus solitarii
Identification and localization of cell types that express endothelial and neuronal nitric oxide synthase in the rat nucleus tractus solitarii
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DOI：
10.1016/j.brainres.2007.07.057
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发表时间：
2007-09-26
期刊：
影响因子：
2.9
通讯作者：
Talman, W. T.
中科院分区：
文献类型：
--
作者：
Lin, L. H.;Taktakishvili, O.;Talman, W. T.
大量研究表明，孤束核（NTS）内的一氧化氮（NO）参与心血管功能的调节。一氧化氮合酶（Nitric oxide synthase，NOS）是合成NO的主要酶，有内皮型NOS（endothelial NOS，eNOS）、神经型NOS（neuronal NOS，nNOS）和诱导型NOS（inducible NOS，iNOS）三种亚型。虽然nNOS在NTS中的分布已被很好地记录，但eNOS在NTS中的分布还没有。由于最近的研究表明，eNOS可能有助于调节压力感受器反射和动脉压，我们研究了eNOS的分布和表达它在大鼠NTS的细胞类型，通过使用多个标签的免疫荧光染色和共聚焦显微镜。eNOS和nNOS的免疫反应（IR）被发现在所有NTS亚核的细胞和过程中，但eNOS-IR比nNOS-IR更均匀地分布。虽然含有eNOS-IR或nNOS-IR的结构往往存在于紧密的接近，他们从来没有包含两种亚型。几乎所有的eNOS-IR阳性结构，但没有nNOS-IR阳性结构，含有神经胶质标记物胶质细胞酸性蛋白的IR。此外，虽然所有nNOS-IR阳性细胞含有神经元标记物神经元核抗原（NeuN）的IR，但没有eNOS-IR阳性细胞含有NeuN-IR。我们得出结论，NTS中的eNOS仅存在于星形胶质细胞和内皮细胞中，而不存在于神经元中。我们的数据补充了以前的生理学研究，并表明，虽然NO从nNOS可以直接调节NTS中的神经传递，NO从eNOS在NTS中可以通过星形胶质细胞和神经元之间的相互作用来调节心血管功能。(c)2007 Elsevier B. V.保留所有权利。
Numerous studies have suggested that nitric oxide (NO) in the nucleus tractus solitarii (NTS) participates in modulating cardiovascular function. Nitric oxide synthase (NOS), the enzyme responsible for synthesis of NO, exists in 3 isoforms: endothelial NOS (eNOS), neuronal NOS (nNOS), and inducible NOS (iNOS). Although the distribution of nNOS in the NTS has been well documented, the distribution of eNOS in the NTS has not. Because recent studies have shown that eNOS may contribute to regulation of baroreceptor reflexes and arterial pressure, we examined the distribution of eNOS and the types of cells that express it in rat NTS by using multiple labels for immunofluorescent staining and confocal microscopy. Immunoreactivity (IR) for eNOS and nNOS was found in cells and processes in all NTS subnuclei, but eNOS-IR was more uniformly distributed than was nNOS-IR. Although structures containing either eNOS-IR or nNOS-IR were often present in close proximity, they never contained both isoforms. Almost all eNOS-IR positive structures, but no nNOS-IR positive structures, contained IR for the glial marker glial fibrillary acidic protein. Furthermore, while all nNOS-IR positive cells contained IR for the neuronal marker neuronal nuclear antigen (NeuN), none of the eNOS-IR positive cells contained NeuN-IR. We conclude that eNOS in the NTS is present only in astrocytes and endothelial cells, not in neurons. Our data complement previous physiological studies and suggest that although NO from nNOS may modulate neurotransmission directly in the NTS, NO from eNOS in the NTS may modulate cardiovascular function through an interaction between astrocytes and neurons. (c) 2007 Elsevier B.V. All rights reserved.