Nichols K, Staines W, Rubin S, Krantis A
Department of Physiology, Faculty of Medicine, University of Ottawa, Ontario, Canada.
Am J Physiol. 1994 Aug;267(2 Pt 1):G270-5. doi: 10.1152/ajpgi.1994.267.2.G270.
NO is produced within peripheral blood vessels through the action of the differentially distributed constitutive and inducible NO synthase isoforms in the vessel wall. As in other sites in the periphery, NO exerts local vasodilatory actions in the gastrointestinal microvasculature and is proposed to play a role in enteric vasomotor regulation. Using NO synthase histochemistry and endothelial cell immunohistochemistry, we provide the first anatomic evidence of NO synthesis in both endothelial and smooth muscle cells of submucosal blood vessels in the rat and human intestine. The findings of this study indicate that 1) as in the periphery, both the endothelial and vascular smooth muscle cells of the microvessels irrigating the rat and human intestinal wall possess NO synthesis potential, 2) NO synthase activity is predominantly localized to discrete subcellular patches, and 3) the source of NO within the vascular wall, either intimal or medial, should be a consideration in future studies in terms of the relative contribution of these sources of vasomotor tone in the rat and human gut wall.
一氧化氮（NO）通过血管壁中分布不同的组成型和诱导型一氧化氮合酶亚型的作用在外周血管内产生。与外周其他部位一样，NO在胃肠道微血管中发挥局部血管舒张作用，并被认为在肠道血管运动调节中起作用。利用一氧化氮合酶组织化学和内皮细胞免疫组织化学，我们首次提供了解剖学证据，证明大鼠和人类肠道黏膜下血管的内皮细胞和平滑肌细胞中均有NO合成。本研究结果表明：1）与外周一样，灌注大鼠和人类肠壁的微血管的内皮细胞和血管平滑肌细胞均具有NO合成潜力；2）一氧化氮合酶活性主要定位于离散的亚细胞斑块；3）就这些血管运动张力来源在大鼠和人类肠壁中的相对贡献而言，血管壁内（无论是内膜还是中膜）NO的来源应在未来研究中予以考虑。
