Lew R, Grigoriadis D E, Sharkey J, Kuhar M J
Neuroscience Branch, National Institute on Drug Abuse, Baltimore, Maryland 21224.
Synapse. 1989;3(4):372-5. doi: 10.1002/syn.890030411.
3H-GBR 12935 was used to label the digitonin-solubilized dopamine transporter from dog caudate nucleus. Specific binding to soluble fractions was observed in dog caudate but was absent in rat cerebellum. Binding to the solubilized transporter sites was saturable and of high affinity (Bmax = 2.57 +/- 0.60 pmol/mg protein, KD = 23.42 +/- 2.24 nM, n = 4). Heating or addition of trypsin abolished specific binding in the soluble fractions. In competition studies, soluble 3H-GBR 12935 binding was inhibited by mazindol, GBR 12909, nomifensine, dimethocaine, dopamine, (-) cocaine, and (+) cocaine in a manner typical of binding to the dopamine transporter. As expected, tomoxetine and citalopram, inhibitors of norepinephrine and serotonin uptake, respectively, were weak competitors of 3H-GBR 12935 binding.
用3H-GBR 12935标记犬尾状核中经洋地黄皂苷增溶的多巴胺转运体。在犬尾状核中观察到与可溶部分的特异性结合，但在大鼠小脑中不存在。与增溶的转运体位点的结合是可饱和的且具有高亲和力（Bmax = 2.57 +/- 0.60 pmol/mg蛋白质，KD = 23.42 +/- 2.24 nM，n = 4）。加热或添加胰蛋白酶可消除可溶部分中的特异性结合。在竞争研究中，可溶的3H-GBR 12935结合受到吗茚酮、GBR 12909、诺米芬辛、地美卡因、多巴胺、（-）可卡因和（+）可卡因的抑制，其方式为典型的与多巴胺转运体的结合。正如预期的那样，分别作为去甲肾上腺素和5-羟色胺摄取抑制剂的托莫西汀和西酞普兰是3H-GBR 12935结合的弱竞争者。
