Localization of the extracellular Ca2+-sensing receptor and PTH/PTHrP receptor in rat kidney
Localization of the extracellular Ca2+-sensing receptor and PTH/PTHrP receptor in rat kidney
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DOI：
10.1152/ajprenal.1996.271.4.f951
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发表时间：
1996-10-01
影响因子：
4.2
通讯作者：
Hebert, SC
中科院分区：
文献类型：
--
作者：
Riccardi, D;Lee, WS;Hebert, SC
利用与我们之前鉴定的牛甲状旁腺Ca2+感应受体同源性的策略(5)，我们最近从大鼠肾脏中分离出细胞外，G蛋白偶联的Ca2+/多价阳离子感应受体RaKCaR（22）。该受体在肾脏中的定位和生理作用尚不清楚。在本研究中，我们通过原位杂交和微解剖肾元片段的逆转录聚合酶链反应，评估了RaKCaR和甲状旁腺激素/甲状旁腺激素相关蛋白（PTH/PTHrP）受体mrna沿大鼠肾元的分布。我们的研究结果表明，这两种受体的转录本在肾小球、近曲小管、近直小管、皮质厚升肢、远曲小管和皮质集管共表达。此外，在髓厚升肢、外髓和内髓集管中发现了RaKCaR转录本（但未发现PTH/PTHrP受体）。这些发现提出了RaKCaR不仅在调节二价矿物质重吸收，而且在水重吸收和尿浓度中发挥作用的可能性。综上所述，我们的研究结果为理解高钙血症对激素刺激的盐和水运输的影响提供了新的见解。
Using a strategy based on homology to the bovine parathyroid Ca2+-sensing receptor previously identified by us (5), we have recently isolated an extracellular, G protein-coupled Ca2+/polyvalent cation-sensing receptor, RaKCaR (22), from rat kidney. The localization and physiological role(s) of this receptor in the kidney are not well understood. In the present study, we assessed the distribution of mRNAs for RaKCaR and the parathyroid hormone/parathyroid hormone-related protein (PTH/PTHrP) receptor along the rat nephron by in situ hybridization and reverse transcriptase-polymerase chain reaction of microdissected nephron segments. Our results show that transcripts for both receptors coexpress at glomeruli, proximal convoluted tubule, proximal straight tubule, cortical thick ascending limb, distal convoluted tubule, and cortical collecting duct. In addition, RaKCaR (but not PTH/PTHrP receptor) transcripts were found in the medullary thick ascending limb and outer medullary and inner medullary collecting ducts. These findings raise the possibility of roles for RaKCaR not only in the regulation of divalent mineral reabsorption but also in water reabsorption and urinary concentration. Taken together, our results provide new insights in understanding the effects of hypercalcemia on hormone-stimulated salt and water transport.