DEMONSTRATION OF HIGH-AFFINITY AND LOW-AFFINITY BETA-ADRENERGIC RECEPTORS IN SLIDE-MOUNTED SECTIONS OF RAT AND HUMAN BRAIN
DEMONSTRATION OF HIGH-AFFINITY AND LOW-AFFINITY BETA-ADRENERGIC RECEPTORS IN SLIDE-MOUNTED SECTIONS OF RAT AND HUMAN BRAIN
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DOI：
10.1016/0006-8993(90)90904-p
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发表时间：
1990-05-14
期刊：
影响因子：
2.9
通讯作者：
MANN, JJ
中科院分区：
文献类型：
--
作者：
ARANGO, V;ERNSBERGER, P;MANN, JJ
使用分离的细胞膜的研究已经显示β-肾上腺素能受体以两种可相互转换的构象存在，一种对激动剂具有高亲和力，另一种具有低亲和力。鸟嘌呤核苷酸和钠将高亲和力受体位点转移到低亲和力位点。我们试图证明β-半乳糖苷酶的亲和力状态。肾上腺素能受体在大鼠和人死后脑的载玻片切片中的分布，并使用定量受体放射自显影术确定高亲和力受体相对于β-肾上腺素能受体的总群体在脑中的区域分布。肾上腺素能受体β-肾上腺素能激动剂异丙肾上腺素以双相方式抑制125 I-碘吲哚洛尔与大鼠前脑和人前运动皮质的载玻片切片的结合。大约80%的β-大鼠和人脑中的受体位点对异丙肾上腺素显示出高亲和力（7 - 14 nM）。用0.1 mM不可水解的鸟嘌呤核苷酸5 "-鸟苷酰亚氨基二磷酸和25 mM NaCl处理可消除大鼠脑切片中的高亲和力结合，并降低人脑切片中的高亲和力结合。这些发现通过使用类似组织样本的膜研究得到证实。对于放射自显影研究，17 nM异丙肾上腺素置换了71%的高亲和力β-受体。肾上腺素能受体数字减影用于选择性地可视化β-高亲和力构象的受体。β-的比例高亲和力构象的肾上腺素能受体在大鼠脑区域和人类皮质层之间存在显著差异。我们得出α-肾上腺素能亲和力状态，可能反映了受体与G蛋白的相互作用，发生在大鼠脑的切片中，并持续存在于人类死后材料中。受体亲和力统计的定量受体放射自显影分析可能比单独测定结合位点密度提供更好的受体功能指标。这项工作以前是以抽象的形式提出的3。
Studies using isolated cell membranes have shown the .beta.-adrenergic receptors exist in two interconvertible conformations, one with high affinity for agonists and the other with low affinity. Guanine nucleotides and sodium shift high-affinity receptor sites into low-affinity sites. We sought to demonstrate affinity states of the .beta.-adrenergic receptor in slide-mounted sections of rat and human postmortem brain, and to determine using quantitative receptor autoradiography the regional distribution in the brain of high-affinity receptors relative to the total population of .beta.-adrenergic receptors. The .beta.-adrenergic agonist isoproterenol inhibited the binding of 125I-iodopindolol to slide-mounted sections of rat forebrain and human premotor cortex in a biphasic manner. Approximately 80% of the .beta.-receptor sites in both rat and human brain showed high-affinity for isoproterenol (7-14 nM). Treatment with 0.1 mM non-hydrolyzable guanine nucleotide 5''-guanylylimidodiphosphate and 25 mM NaCl abolished high-affinity binding in rat brain sections and reduced it in human brain sections. These findings were confirmed by membrane studies using similar tissue samples. For autoradiographic studies, 17 nM isoproterenol displaced 71% of the high-affinity .beta.-adrenergic receptors. Digital subtraction was used to selectively visualize .beta.-receptors in the high-affinity conformation. The proportion of .beta.-adrenergic receptors in the high-affinity conformation differed significantly across rat brain regions and across human cortical layers. We conclude the .alpha.-adrenergic affinity states, presumably reflecting the interaction of the receptor with a G-protein, occur in slide-mounted section sof rat brain and persist in human postmortem material. Quantitative recceptor autoradiographic analysis of receptor affinity stats may provide a better index of receptor function than determination of binding site density alone. This work was previously presented in abstract form3.