Criado M, Aguilar J S, De Robertis E
J Neurobiol. 1981 May;12(3):259-67. doi: 10.1002/neu.480120306.
3H-naloxone specific binding was carried out on synaptosomal membranes isolated from basal ganglia of the cat brain. A high- and a low-affinity site with Kd1 = 3.7 nM and Kd2 = 35 nM having B max 1 = 79 pmole/g protein and B max 2 = 224 pmole/g protein were found. The Hill number for the high- and low-affinity sites were, respectively, 1.01 and 0.86. Digitonin and Triton X-100 had an inhibitory effect on the binding at concentrations between 10(-5) and 10(-1)% (w/v). Deoxycholate and Nonidet P-40 also inhibited the binding of 3H-naloxone, but at 10(-4)% produced a 50% enhancement. After the binding to membranes, the 3H-naloxone receptor complex is stable to the action of Triton X-100 and dissociates slowly. In membranes bound with 10 nM 3H-naloxone and then submitted to 0.1-0.2% Triton X-100, in which only the presynaptic membrane disintegrates, the specific radioactivity is decreased. With a more drastic treatment that disintegrates the postsynaptic membrane, the 3H-naloxone binding to synaptosomal membranes is almost completely abolished. These results suggest that opiate receptors may be localized both pre- and postsynaptically in central synapses.
对从猫脑基底神经节分离出的突触体膜进行了³H-纳洛酮特异性结合实验。发现了一个高亲和力位点和一个低亲和力位点，其解离常数Kd1 = 3.7 nM，Kd2 = 35 nM，最大结合容量B max 1 = 79 pmol/g蛋白质，B max 2 = 224 pmol/g蛋白质。高亲和力位点和低亲和力位点的希尔系数分别为1.01和0.86。洋地黄皂苷和曲拉通X-100在浓度为10⁻⁵至10⁻¹%（w/v）之间时对结合有抑制作用。脱氧胆酸盐和诺乃洗涤剂P-40也抑制³H-纳洛酮的结合，但在10⁻⁴%时却能使结合增强50%。³H-纳洛酮与膜结合后，其受体复合物对曲拉通X-100的作用稳定且解离缓慢。在与10 nM³H-纳洛酮结合的膜中，然后用0.1 - 0.2%的曲拉通X-100处理，此时只有突触前膜解体，比放射性降低。用更剧烈的处理使突触后膜解体时，³H-纳洛酮与突触体膜的结合几乎完全被消除。这些结果表明阿片受体可能定位于中枢突触的突触前和突触后部位。
