人虹膜中外周型苯二氮䓬拮抗剂（[3H]PK 11195）的结合位点

Binding sites for a peripheral type benzodiazepine antagonist ([3H]PK 11195) in human iris.

作者信息

Valtier D, Malgouris C, Gilbert J C, Guicheney P, Uzan A, Gueremy C, Le Fur G, Saraux H, Meyer P

出版信息

Neuropharmacology. 1987 Jun;26(6):549-52. doi: 10.1016/0028-3908(87)90146-8.

Abstract

Peripheral-type benzodiazepine binding sites have been characterized on sections of 8 normal human iris/ciliary-body preparations. Saturability was determined at 25 degrees C with [3H] PK 11195 (1 nM) a specific ligand of peripheral type sites. The studies revealed a single class of binding sites for PK 11195 with a nanomolar range affinity (KD = 1.45 nM) and a maximal capacity (Bmax) of 35.5 fmol/mg protein. The displacement potency order of the benzodiazepines tested suggest that these sites belong to the peripheral type: PK 11211 (IC50 = 12 nM) greater than Ro 5-4864 (IC50 = 770 nM) greater than clonazepam (IC50 = 20,000 nM). The present data demonstrate that high affinity binding sites for peripheral type benzodiazepines are present in human iris/ciliary-body. This tissue is therefore a suitable tool for evaluation of the putative functional role of these binding sites.

摘要

已对8份正常人虹膜/睫状体标本切片上的外周型苯二氮䓬结合位点进行了表征。在25℃下，用外周型位点的特异性配体[3H] PK 11195（1 nM）测定饱和度。研究揭示了PK 11195的一类结合位点，其亲和力在纳摩尔范围内（KD = 1.45 nM），最大容量（Bmax）为35.5 fmol/mg蛋白质。所测试的苯二氮䓬的置换效力顺序表明这些位点属于外周型：PK 11211（IC50 = 12 nM）大于Ro 5-4864（IC50 = 770 nM）大于氯硝西泮（IC50 = 20,000 nM）。目前的数据表明，人虹膜/睫状体中存在外周型苯二氮䓬的高亲和力结合位点。因此，该组织是评估这些结合位点假定功能作用的合适工具。