Regulation of blood pressure by glomus cells distributed in the artery

鸡的甲状腺、甲状旁腺、头腺和尾腺、颈动脉体和鳃末腺沿颈总动脉呈连续系列分布。这些器官有分支这些分支由颈总动脉中部的主干组成。鸡颈动脉小体血管球细胞对血清素表现出强烈的免疫反应性。此外，血清素免疫反应细胞广泛分布于颈总动脉壁及其供应内分泌器官的分支（Kameda, 1990a）。我曾在光镜下报道过位于颈总动脉壁及其分支的血管球细胞表达神经肽Y （NPY）的免疫反应性（Kameda, 1990b）。本研究采用包埋后免疫金标记法在电镜水平上检测了NPY在肾小球细胞中的定位。代表NPY免疫反应性的金颗粒仅位于球囊细胞的分泌颗粒上。此外，通过原位杂交和northern blot分析研究了NPY基因的表达。用地高辛标记的鸡NPY外显子2合成寡核苷酸探针原位杂交研究表明，标记细胞的分布与免疫组织化学相似。此外，用鸡NPY外显子4探针进行northern blot分析也支持了这些数据。提取鸡颈总动脉及其分支mRNA，纯化poly (A) ^+RNA。在提取物中获得了NPY基因的特异条带。这些结果提供了分布在颈总动脉及其分支的血管球细胞合成和分泌NPY的证据。众所周知，NPY是一种有效的血管收缩剂。动脉内及周围的血管球细胞可能参与动脉血流的调节。

In the chicken, the thyroid gland, cranial and caudal parathyroid glands, carotid body and ultimobranchial gland are situated as a continuous series along the common carotid artery. The organs are supplied with branches that arise by one trunk from the middle portion of the common carotid artery. The glomus cells of the chicken carotid body express intense immunoreactivity for serotonin. Furthermore, serotonin-immunoreactive cells are widely ditributed in the wall of the common carotid artery and its branches supplying the endocrine organs (Kameda, 1990a). I have previously reported at the light microscopic level that glomus cells located in the wall of the common carotid artery and its branches express immunoreactivity for neuropeptide Y (NPY) (Kameda, 1990b). The present study examined the localization of NPY in the glomus cells at the electron microscopic level with the postembedding immunogold labeling. Gold particles representing NPY immunoreactivity were located exclusively on the secretory granules of the glomus cells. Furthermore, NPY gene expression was studied by means of in situ hybridization and northern blot analysis. In situ hybridization study with digoxigenin-labeled synthetic oligonucletotide probes from chicken NPY exon 2 indicated that the distribution of labeled cells was similar to that with immunohistochemistry. In addition, the data were supported by northern blot analysis with a chicken NPY exon 4 probe. mRNA from chicken common carotid artery and its branches was extracted and poly (A) ^+RNA was purified. The specific band for NPY gene was obtained in the extracts. These results provide the evidence that glomus cells distributed in the common carotid artery and its branches systhesize and secrete NPY.It is well known that NPY is a potent vasoconstrictor. The glomus cells in and around arteries may be involved in the regulation of arterial blood flow.