Autoradiographic localization of dopamine D1 receptors in the human kidney.
Autoradiographic localization of dopamine D1 receptors in the human kidney.
复制标题
人肾中多巴胺 D1 受体的放射自显影定位。
DOI：
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发表时间：
1993
影响因子：
3.5
通讯作者：
F. Amenta
中科院分区：
文献类型：
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作者：
A. Ricci;S. Escaf;J. Vega;F. Amenta
采用体外放射受体结合和放射自显影相结合的方法，在人肾冰冻切片上研究了选择性D_1受体拮抗剂[3H][R]-(+)-8-chloro-2，3，4，5-tetrahydro-5-phenyl-1H-3-benzazepin-7-al-SCH_(23390)的药理分布和解剖定位。[~3H]SCH 23390与人肾切片结合的方式与D1位点的标记方式一致，其Kd值为3.87 nM，Bmax为143fmol/mg蛋白。光镜放射自显影显示致密黄斑和近端小管[~3H]-SCH-23390结合位点密度最高，其次为Henle环升支、远端小管和Henle环降支。在肾小球或集合管上皮内没有明显的特异性结合。在肾内动脉分支的内侧层也观察到SCH-23390结合位点。这些发现表明，人类肾脏中的多巴胺D1受体位置具有与实验室哺乳动物相似的定位，其管状受体密度高于血管受体密度。上述数据解释了刺激人类的D1受体所引起的血管、利尿和利钠作用。
The pharmacological profile and the anatomical localization of the selective D1-receptor antagonist [3H][R]-(+)-8-chloro-2,3,4,5-tetrahydro-5-phenyl-1H-3-benzazepin-7 -al- hemimaleate ([3H]SCH 23390) were studied in frozen sections of human kidney by using combined in vitro radioreceptor binding and autoradiographic techniques. [3H]SCH 23390 was bound by sections of human kidney in a manner consistent with the labeling of D1 sites, with a Kd value of 3.87 nM and with a Bmax value of 143 fmol/mg protein. Light microscope autoradiography revealed the highest density of [3H]SCH 23390 binding sites within the macula densa and the proximal tubules followed in descending order by the ascending limb of the loop of Henle, the distal tubules and the descending limb of the loop of Henle. No specific binding was noticeable within the glomeruli or within the epithelium of collecting tubules. [3H]SCH 23390 binding sites were also observed within the medial layer of intrarenal artery branches. These findings show that dopamine D1 receptor sites in the human kidney have a localization similar to that described in laboratory mammals with a higher density of tubular than of vascular receptors. The above data account for the vascular, diuretic and natriuretic effects elicited by D1 receptor stimulation in man.