Differences in photoaffinity labeling of DA1 receptors in renal proximal tubules from normotensive rat and SHR.
Differences in photoaffinity labeling of DA1 receptors in renal proximal tubules from normotensive rat and SHR.
复制标题
正常血压大鼠和 SHR 肾近曲小管 DA1 受体光亲和标记的差异。
DOI：
10.1152/ajprenal.1995.268.6.f1009
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Sidhu,A
中科院分区：
文献类型：
--
作者：
Vachvanichsanong,P;Kimura,K;Sidhu,A
Renal DA1 dopamine receptors in proximal tubule membranes of normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were characterized with the novel D1 dopamine receptor-selective photoaffinity probe, (+/-)-7-[125I]iodo-8-hydroxy-3-methyl-1-(4-azidophenyl)-2,3,4,5- tetrahydro-1H-3-benzazepine ([125I]MAB). Under nonphotolyzing conditions, saturation studies showed that [125I]MAB bound with similar affinity to DA1 dopamine receptors in both WKY [dissociation constant (Kd) = 16.3 nM] and SHR (Kd = 19.5 nM). At photolysis, [125I]MAB was irreversibly incorporated into a single major protein of 74,000 Da in both WKY and SHR. DA1-selective antagonists blocked photolabeling of DA1 sites with similar efficiency and specificity in SHR and WKY. However, under identical assay conditions, dopaminergic agonists were unable to block photoincorporation of [125I]MAB in SHR but not in WKY. This pattern of labeling of DA1 sites by [125I]MAB may suggest the presence of defective agonist, but not antagonist, binding domains on the receptor in SHR but not in WKY rats.
