Niwa M, Kawaguchi T, Himeno A, Fujimoto M, Kurihara M, Yamashita K, Kataoka Y, Shigematsu K, Taniyama K
Department of Pharmacology 2, Nagasaki University School of Medicine, Japan.
Eur J Pharmacol. 1992 Apr 10;225(4):281-9. doi: 10.1016/0922-4106(92)90101-z.
Specific binding sites for 125I-endothelin-1 (125I-ET-1) in the spinal cord were investigated using quantitative receptor autoradiographic and chemical cross-linking methods. The binding sites were highly concentrated in porcine and human spinal cord areas corresponding anatomically to the dorsal horn (Rexed's laminae I-III), an area around the central canal (lamina X) and the principal part of the intermediolateral nucleus (IMLp). The localization of the binding sites differed from those of 125I-omega-conotoxin GVIA (125I-CgTx) and 125I-Bolton-Hunter substance P (125I-BH-SP), with the exception that the IMLp shared 125I-ET-1 with 125I-CgTx and 125I-BH-SP binding sites. Specific 125I-ET-1 binding sites in the areas examined were characteristically single and of high affinity. There were no differences between the potencies of unlabeled ET family peptides, ET-1, ET-2, ET-3 and sarafotoxin S6b at inhibiting 125I-ET-1 binding to the areas. Chemical cross-linking studies showed that 125I-ET-1 and 125I-ET-3 mainly bound to a protein with molecular mass of 43 kDa in the porcine and human thoracic spinal cord membranes. The present finding shows the neuronal significance of this newly discovered peptide in the spinal cord.
采用定量受体放射自显影和化学交联方法，研究了脊髓中125I-内皮素-1（125I-ET-1）的特异性结合位点。这些结合位点高度集中在猪和人脊髓中与背角（Rexed板层I-III）、中央管周围区域（板层X）以及中间外侧核主要部分（IMLp）在解剖学上相对应的区域。结合位点的定位与125I-ω-芋螺毒素GVIA（125I-CgTx）和125I-博尔顿-亨特P物质（125I-BH-SP）的不同，不过IMLp与125I-CgTx和125I-BH-SP的结合位点有共同的125I-ET-1。在所研究区域中的特异性125I-ET-1结合位点具有单一且高亲和力的特征。未标记的ET家族肽ET-1、ET-2、ET-3和铃蟾毒素S6b在抑制125I-ET-1与这些区域结合的效力上没有差异。化学交联研究表明，125I-ET-1和125I-ET-3主要与猪和人胸段脊髓膜中分子量为43 kDa的一种蛋白质结合。本研究结果显示了这种新发现的肽在脊髓中的神经元意义。
