Dikranian K, Tomlinson A, Loesch A, Winter R, Burnstock G
Department of Anatomy and Developmental Biology, University College London, UK.
J Anat. 1994 Dec;185 ( Pt 3)(Pt 3):609-15.
Endothelin-1 is thought to play a role in the regulation of gastrointestinal function including its secretory role. This study investigated the localisation of endothelin-1 in the mucosa of the large intestine of normoxic and chronically hypoxic rats. Chronic hypoxia was produced by maintaining the animals in a hypoxic chamber. After animal perfusion/fixation, colonic segments from normoxic and hypoxic rats were investigated by the postembedding immunogold labelling procedure. In the microvasculature from normoxic (control) animals immunolabelling visualised as single particles was low and confined to the cytoplasm of endothelial cells. In the epithelium, immunolabelling was found mainly at the basal and apical regions of the cells. Chronic hypoxia for 10 d greatly enhanced the level of immunolabelling both in endothelial and epithelial cells of the mucosa. In endothelial cells clusters of gold particles were found in the cytoplasmic matrix and the subendothelium. Epithelial cells showed intense labelling, located mainly in the luminal/apical region within vacuole-like spaces and in the brush-border. In conclusion, hypoxia induces increase in immunoreactivity to endothelin-1 in gut endothelial and especially epithelial cells in the colonic mucosa.
内皮素-1被认为在包括其分泌作用在内的胃肠功能调节中发挥作用。本研究调查了常氧和慢性缺氧大鼠大肠黏膜中内皮素-1的定位。通过将动物置于缺氧舱中制造慢性缺氧。在动物灌注/固定后，采用包埋后免疫金标记法对常氧和缺氧大鼠的结肠段进行研究。在常氧（对照）动物的微血管中，以单个颗粒形式可视化的免疫标记较低，且局限于内皮细胞的细胞质。在上皮中，免疫标记主要见于细胞的基底和顶端区域。10天的慢性缺氧极大地增强了黏膜内皮细胞和上皮细胞中的免疫标记水平。在内皮细胞中，金颗粒簇见于细胞质基质和内皮下。上皮细胞显示出强烈的标记，主要位于液泡样空间内的腔面/顶端区域和刷状缘。总之，缺氧诱导结肠黏膜中肠道内皮细胞尤其是上皮细胞对内皮素-1的免疫反应性增加。
