Madras B K, Davis A, Seeman P
Eur J Pharmacol. 1982 Mar 26;78(4):431-8. doi: 10.1016/0014-2999(82)90485-x.
In order to determine the species which would provide the highest yield of soluble and specific D2-type dopamine receptors, the striata from human, calf and canine brains were solubilized by 1% digitonin. The receptors were detected with [3H]spiperone, using Sephadex G-50 columns or polyethylene glycol precipitation. The soluble D2-sites from the human and canine tissue had about the same KD and rank order of drug affinities as the native membrane preparations. The binding characteristics of the calf D2-receptors were considerably altered, however, upon solubilization; the affinities for spiperone and chloropromazine were reduced 12-fold, and the non-specific binding increased from 28 to 50%. Calf caudate is a poor choice for dopamine receptor solubilization using digitonin. The solubilized canine tissue, however, provided an excellent source of D2-receptors because of its similarity to soluble human D2-receptors and its stability in solution.
为了确定能提供最高产量的可溶性特异性D2型多巴胺受体的物种，用人、小牛和犬脑的纹状体，通过1%洋地黄皂苷进行溶解。使用Sephadex G-50柱或聚乙二醇沉淀法，用[3H]螺哌隆检测受体。来自人和犬组织的可溶性D2位点与天然膜制剂具有大致相同的解离常数（KD）和药物亲和力排序。然而，小牛D2受体在溶解后，其结合特性发生了显著改变；对螺哌隆和氯丙嗪的亲和力降低了12倍，非特异性结合从28%增加到50%。使用洋地黄皂苷溶解多巴胺受体时，小牛尾状核不是一个好的选择。然而，溶解后的犬组织因其与可溶性人D2受体相似且在溶液中稳定，成为了D2受体的优质来源。
