Jimenez Aguilar C, De Robertis E
Eur J Pharmacol. 1982 Apr 8;79(1-2):1-9. doi: 10.1016/0014-2999(82)90568-4.
[3H]Spiroperidol binding was used to assay dopaminergic receptors in synaptosomal membranes isolated from basal ganglia of cat brain. In addition to the usual filtration, a special centrifugation technique was developed which has some advantages for ligands with high non-specific binding. The specific binding to control membranes showed a high affinity binding site with KD 0.99 nM and Bmax 445 fmol/mg protein, both determined by Scatchard analysis. Addition of 10(-5) -10(-3)% Triton X-100 increased the Bmax of the high affinity binding site without a change in KD. With higher concentrations of detergent (10(-2) -10 (-1)% there was inhibition of binding. Both the activation and the inhibition of binding were reversed by washing of the detergent; but the reversal of the activation was accompanied by a decrease in affinity. The binding to synaptosomal membranes treated with 10(-1) - 10(-2)% Triton X-100 and then washed led to a loss of receptors probably present in the presynaptic membrane. These and other results suggest that dopaminergic receptors are localized both pre- and postsynaptically in relation to the synaptic region.
利用[3H]螺哌啶醇结合法对从猫脑基底神经节分离的突触体膜中的多巴胺能受体进行测定。除常规过滤外，还开发了一种特殊的离心技术，该技术对于具有高非特异性结合的配体具有一些优势。与对照膜的特异性结合显示出一个高亲和力结合位点，通过Scatchard分析确定其KD为0.99 nM，Bmax为445 fmol/mg蛋白。加入10^(-5)-10^(-3)%的 Triton X-100可增加高亲和力结合位点的Bmax，而KD不变。当洗涤剂浓度更高（10^(-2)-10^(-1)%）时，结合受到抑制。结合的激活和抑制均可通过洗涤洗涤剂来逆转；但激活的逆转伴随着亲和力的降低。与用10^(-1)-10^(-2)% Triton X-100处理然后洗涤的突触体膜的结合导致可能存在于突触前膜中的受体丢失。这些以及其他结果表明，多巴胺能受体在突触区域的突触前和突触后均有定位。
