Zhao Y D, Xu L X, Chandler J W
Department of Ophthalmology and Visual Sciences, UIC Eye Center, University of Illinois at Chicago, USA.
J Cardiovasc Pharmacol. 1995;26 Suppl 3:S332-5.
Immunohistochemistry and in vitro autoradiographic techniques were used to investigate the localization of endothelin (ET)-like immunoreactivity and [125I]ET-1 binding sites in sections of ocular tissues of normal rabbits. ET-like immunoreactivity was localized to the corneal endothelium and the pre-epithelial layer of the cornea, which was specifically inhibited by addition of exogenous ET-1. Immunoreactivity for ET was also observed in the retinal ganglion layer and periocular fat tissues. These, however, were not inhibited in the presence of ET-1. Autoradiography showed binding sites for ET-1 in the iris and ciliary body. Emulsion-dipped slides of sections of rabbit eyes incubated with [125I]ET-1 showed specific labeling for binding sites over structures that were identified from serial sections stained with hematoxylineosin. These were the anterior stroma of the iris root, the walls of capillaries, the circular arteries, and the veins of the ciliary body and extraocular muscles. No binding sites were found in the cornea or conjunctiva. The difference in regional distributions of ET storage and binding sites in rabbit ocular tissue suggests that the peptide may have specific physiologic functions.
采用免疫组织化学和体外放射自显影技术，研究正常兔眼组织切片中内皮素（ET）样免疫反应性和[125I]ET-1结合位点的定位。ET样免疫反应性定位于角膜内皮和角膜上皮前层，添加外源性ET-1可特异性抑制该反应。在视网膜神经节层和眼周脂肪组织中也观察到ET免疫反应性。然而，在ET-1存在的情况下，这些反应并未受到抑制。放射自显影显示虹膜和睫状体中有ET-1结合位点。用[125I]ET-1孵育的兔眼切片的乳胶浸渍玻片显示，在苏木精-伊红染色的连续切片中鉴定出的结构上，结合位点有特异性标记。这些结构是虹膜根部的前基质、毛细血管壁、睫状体和眼外肌的环形动脉和静脉。在角膜或结膜中未发现结合位点。兔眼组织中ET储存和结合位点的区域分布差异表明，该肽可能具有特定的生理功能。
