Optimization of radioligand binding assays for I1-imidazoline sites.
Optimization of radioligand binding assays for I1-imidazoline sites.
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I1-咪唑啉位点放射性配体结合测定的优化。
DOI：
10.1111/j.1749-6632.1995.tb32402.x
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发表时间：
1995
影响因子：
5.2
通讯作者：
Graves,ME
中科院分区：
文献类型：
--
作者：
Ernsberger,P;Piletz,JE;Graff,LM;Graves,ME
在牛脑干延髓头端腹外侧（RVLM）的细胞膜中，[3 H]可乐定以几乎相等的纳摩尔亲和力与α 2-肾上腺素能和1，1-咪唑啉结合。人血小板11-咪唑啉位点也已得到表征，与牛RVLM位点几乎相同，因为pKi值的相关系数超过0.9。[6]尽管11-咪唑啉结合位点的细胞特异性表达及其可能的生物活性的证据越来越多，但几个研究小组仍难以用放射性标记的可乐定类似物标记11-位点。例如，牛肾上腺髓质嗜铬细胞缺乏[3 H]可乐定？尽管在同样制备的细胞上发现了丰富的11-咪唑啉位点。[6]其他人报道了[3 H]可乐定的低亲和力（> 20 nM）高容量结合位点，就咪唑啉的总体亲和力和效力顺序而言，这些位点与11-或12-咪唑啉亚型明显不同，暂时称为“Is-咪唑啉结合位点”。6在这一系列实验中，我们优化了选择性标记高亲和力11-咪唑啉位点的条件。
In cell membranes from the rostral ventrolateral medulla oblongata (RVLM) of bovine brainstem,[3H] clonidine binds with nearly equal nanomolar affinities to both a2-adrenergic and I,-imidazoline Human platelet 11-imidazoline sites have also been characterized and are nearly identical to the bovine RVLM sites, because correlation coefficients for pKi values are over 0.9. 6 Even as evidence accumulates for cell-specific expression of 11-imidazoline binding sites and their probable bioactivity, several groups have had difficulty labeling 11-sites with radiolabeled clonidine analogs. For example, bovine adrenomedullary chromaffin cells were reported to lack specific binding sites for [3H] clonidine? even though abundant 11-imidazoline sites had been found on identically prepared cells. 6 Others report low-affinity (&> 20 nM) highcapacity binding sites for [3H] clonidine which are clearly distinct from either the 11-or 12-imidazoline subtypes in terms of overall affinity and order of potency of the imidazolines and are tentatively termed ‘‘Is-imidazoline binding sites.” 6 In this series of experiments, we optimized conditions for selectively labeling high-affinity 11-imidazoline sites.