Huang Chunfa, Miller R Tyler
Department of Medicine, Case-Western Reserve University, Louis Stokes VAMC, Rammelkamp Center for Research, Metrohealth Medical Center, Cleveland, Ohio, USA.
Curr Opin Nephrol Hypertens. 2007 Sep;16(5):437-43. doi: 10.1097/MNH.0b013e3282b974a6.
Extracellular calcium has profound effects on renal tubular transport, presumably via the calcium-sensing receptor, which is expressed in all nephron segments, but its effects in specific segments and the mechanism of regulation of transport are not fully understood.
Recognition that activating calcium-sensing receptor mutations result in a Bartter-like syndrome demonstrate that the transport effects of extracellular calcium are mediated by the calcium-sensing receptor. Its presence in the gills and solute and water-transporting organs of fish coupled with appropriate calcium-sensing receptor kinetics indicate that the calcium-sensing receptor was originally involved in the regulation of sodium chloride, calcium and magnesium transport. Based on its physiological effects on tubular transport and biochemical and genetic data, the calcium-sensing receptor appears to act by mechanisms that distinguish it from other G protein-coupled receptors.
The calcium-sensing receptor mediates the effects of extracellular calcium on the kidney, is an essential control point in the regulation of calcium balance and possibly the physiological regulation of sodium chloride balance. The thick ascending limb of Henle and distal convoluted tubule appear to be the nephron segments most responsible for the effects of the calcium-sensing receptor, although its mechanisms of action are not fully established.
细胞外钙对肾小管转运有深远影响，可能是通过在所有肾单位节段均有表达的钙敏感受体起作用，但其在特定节段的作用及转运调节机制尚未完全明确。
认识到激活钙敏感受体突变会导致类似巴特综合征的症状，这表明细胞外钙的转运作用是由钙敏感受体介导的。它在鱼类的鳃以及溶质和水转运器官中的存在，再加上适当的钙敏感受体动力学，表明钙敏感受体最初参与氯化钠、钙和镁转运的调节。基于其对肾小管转运的生理作用以及生化和遗传数据，钙敏感受体似乎通过与其他G蛋白偶联受体不同的机制发挥作用。
钙敏感受体介导细胞外钙对肾脏的作用，是钙平衡调节以及可能的氯化钠平衡生理调节中的一个关键控制点。亨氏袢升支粗段和远曲小管似乎是对钙敏感受体作用最负责的肾单位节段，尽管其作用机制尚未完全明确。
