Characterization of binding sites for [3H]spiroperidol.
Characterization of binding sites for [3H]spiroperidol.
复制标题
[3H]螺哌啶醇结合位点的表征。
DOI：
10.1016/0006-2952(87)90642-3
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发表时间：
1987
影响因子：
5.8
通讯作者：
Molinoff,PB
中科院分区：
文献类型：
--
作者：
Luedtke,RR;Molinoff,PB
实验旨在研究从犬尾状核中溶解的[3 H]螺哌利多（[3 H]SPD）结合位点的生化特性，并确定去污剂对放射性配体结合的影响。发现用0.75-1.0%毛地黄皂苷提取犬尾状核产生最大产率的[3 H]SPD结合位点，同时最小化膜蛋白的提取。虽然结合位点用1.0%毛地黄皂苷溶解，但需要将去污剂浓度降低10倍以实现[3 H]SPD的最大结合。对激动剂和拮抗剂的亲和力的等级顺序与多巴胺受体的D2亚型的药理学性质一致。然而，发现拮抗剂的结合是复杂的。对一些混合犬尾状核制剂的研究得出了D2选择性拮抗剂多潘立酮和舒必利的竞争曲线，该曲线最适合单位点模型。其他制剂与这些拮抗剂表现出双相抑制曲线。对D2-选择性拮抗剂具有低亲和力的[3 H]SPD结合位点的类别占结合位点的30-40%。富集的溶解结合位点的[3 H]SPD实现了尺寸排阻HPLC，然后吸附到DEAE-Sephadex和洗脱缓冲液的离子强度增加。结合位点的富集伴随着[3 H]SPD的溶解位点的亲和力的降低。
Experiments were designed to investigate the biochemical properties of binding sites for [3H]spiroperidol ([3H]SPD) solubilized from canine caudate and to define the effect of detergent on the binding of the radioligand. Extraction of canine caudate with 0.75–1.0% digitonin was found to generate the maximum yield of binding sites for [3H]SPD while minimizing extraction of membrane proteins. Although binding sites were solubilized with 1.0% digitonin, a 10-fold reduction in detergent concentration was necessary to achieve maximal binding of [3H]SPD. The rank order of affinity for agonists and antagonists was consistent with the pharmacologie properties of the D2subtype of the dopamine receptor. However, the binding of antagonists was found to be complex. Studies with some preparations of pooled canine caudate resulted in competition curves for the D2-selective antagonists domperidone and sulpiride that best fit a single-site model. Other preparations exhibited biphasic inhibition curves with these antagonists. The class of binding sites for [3H]SPD with low affinity for D2-selective antagonists constituted as much as 30–40% of the binding sites. Enrichment of solubilized binding sites for [3H]SPD was achieved by size exclusion HPLC followed by adsorption to DEAE-Sephadex and elution with buffer of increasing ionic strength. Enrichment of binding sites was accompanied by a decrease in the affinity of solubilized sites for [3H]SPD.