Greney H, Bricca G, Dontenwill M, Stutzmann J, Bousquet P, Belcourt A
Laboratoire de Pharmacologie Cardiovasculaire et Rénale, CNRS URA 589, Faculté de Médecine, Université Louis Pasteur, Strasbourg, France.
Neurochem Int. 1994 Aug;25(2):183-91. doi: 10.1016/0197-0186(94)90038-8.
Imidazoline binding sites from the human brainstem were solubilized with 3-[(3-cholamido-propyl)-dimethylammonio]-1-propane-sulfonate (CHAPS). [3H]idazoxan and [3H]clonidine were used as ligands to characterize the solubilized binding sites. In both the soluble and membrane fractions, [3H]idazoxan binding was saturable, stereoselective, sensitive to imidazolines and insensitive to (-)norepinephrine and to amiloride. The affinities of [3H]idazoxan for the soluble and membrane sites were similar (KD = 25 +/- 11 nM and 20 +/- 3 nM). In both soluble and membrane fractions, the alpha 2-adrenoceptor binding being masked with (-)norepinephrine, [3H]clonidine bound to a low affinity site which was insensitive to (-)norepinephrine and which exhibited the same selectivity for various drugs as the [3H]idazoxan binding site. alpha 2-adrenoceptor binding was present in the membrane and the soluble fractions although it was difficult to detect in the soluble fraction because of inhibition of [3H]rauwolscine binding by the CHAPS detergent.
人脑干中的咪唑啉结合位点用3-[(3-胆酰胺丙基)-二甲基铵]-1-丙烷磺酸盐(CHAPS)进行增溶。[3H]咪唑克生和[3H]可乐定用作配体来表征增溶的结合位点。在可溶性组分和膜组分中，[3H]咪唑克生结合均具有饱和性、立体选择性，对咪唑啉敏感，对(-)去甲肾上腺素和阿米洛利不敏感。[3H]咪唑克生对可溶性位点和膜位点的亲和力相似(KD = 25±11 nM和20±3 nM)。在可溶性组分和膜组分中，α2-肾上腺素能受体结合被(-)去甲肾上腺素掩盖，[3H]可乐定与一个低亲和力位点结合，该位点对(-)去甲肾上腺素不敏感，并且对各种药物表现出与[3H]咪唑克生结合位点相同的选择性。膜组分和可溶性组分中均存在α2-肾上腺素能受体结合，尽管由于CHAPS去污剂对[3H]育亨宾结合的抑制作用，在可溶性组分中难以检测到。
