Czerwiec E, De Backer J P, Flamez A, Vauquelin G
Department of Protein Chemistry, Institute for Molecular Biology and Biotechnology, Free University of Brussels (VUB), St. Genesius Rode, Belgium.
Eur J Pharmacol. 1996 Nov 7;315(1):99-109. doi: 10.1016/s0014-2999(96)00575-4.
"Non-adrenoceptor'-binding sites for [3H]clonidine (I1-sites) and [3H]idazoxan (I2-sites) are identified in calf striatum membranes. The pharmacological profile of both subtypes was investigated by competition binding with the imidazolines idazoxan, cirazoline, Bu 224 (2-(4,5-dihydroimidaz-2-yl)-quinoline) and Bu 239 (2-(4,5-dihydroimidaz-2-yl)-quinoxaline); the guanidino derivatives clonidine, moxonidine, guanabenz, amiloride and agmatine; the oxazoline rilmenidine and the imidazole histamine. The competition experiments indicate that both populations of imidazoline-binding sites in calf striatum consist of a high- (H) and a low-affinity (L) compartment. The monoamine oxidase (MAO) inhibitors pargyline (non-selective) and deprenyl (MAO-B-selective) have micromolar affinity for the I1-sites and much lower affinity for the I2-sites. The venom of the marine snail Conus geographus is the most potent of the 13 tested Conus venom preparations. None of the tested venoms is able to discriminate between both sites.
在小牛纹状体膜中鉴定出了[³H]可乐定（I1位点）和[³H]异喹胍（I2位点）的非肾上腺素能受体结合位点。通过与咪唑啉类药物异喹胍、西拉唑啉、Bu 224（2-(4,5-二氢咪唑-2-基)-喹啉）和Bu 239（2-(4,5-二氢咪唑-2-基)-喹喔啉）；胍基衍生物可乐定、莫索尼定、胍那苄、阿米洛利和胍丁胺；恶唑啉类药物利美尼定以及咪唑类药物组胺进行竞争结合，研究了这两种亚型的药理学特征。竞争实验表明，小牛纹状体中这两种咪唑啉结合位点群体均由高亲和力（H）和低亲和力（L）部分组成。单胺氧化酶（MAO）抑制剂帕吉林（非选择性）和司来吉兰（MAO-B选择性）对I1位点具有微摩尔亲和力，而对I2位点的亲和力则低得多。在13种测试的芋螺毒液制剂中，地纹芋螺毒液的效力最强。所测试的毒液均无法区分这两个位点。
