Friedman P A, Gesek F A
Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, New Hampshire 03755-3835.
Am J Physiol. 1993 Feb;264(2 Pt 2):F181-98. doi: 10.1152/ajprenal.1993.264.2.F181.
Extracellular calcium homeostasis involves coordinated calcium absorption by the intestine, calcium resorption from bone, and calcium reabsorption by the kidney. This review addresses the mechanism and regulation of renal calcium transport. Calcium reabsorption occurs throughout the nephron. However, distal tubules are the nephron site at which calcium reabsorption is regulated by parathyroid hormone, calcitonin, and 1 alpha,25-dihydroxyvitamin D3 and where the magnitude of net reabsorption is largely determined. These and related observations underscore the view that distal tubules are highly specialized to permit fine regulation of calcium excretion in response to alterations in extracellular calcium levels. Progress in understanding the mechanism and regulation of calcium transport has emerged from application of single cell fluorescence, patch clamp, and molecular biological approaches. These techniques permit the examination of ion transport at the cellular level and its regulation at subcellular and molecular levels. This editorial review focuses on recent and emerging observations and attempts to integrate them into models of cellular calcium transport.
细胞外钙稳态涉及肠道对钙的协同吸收、骨钙重吸收以及肾脏对钙的重吸收。本综述探讨肾钙转运的机制与调节。钙重吸收发生于整个肾单位。然而，远曲小管是肾单位中钙重吸收受甲状旁腺激素、降钙素及1α,25 - 二羟维生素D3调节的部位，且净重吸收量在很大程度上由此决定。这些及相关观察结果强调了这样一种观点，即远曲小管高度特化，以允许根据细胞外钙水平的变化对钙排泄进行精细调节。在理解钙转运机制与调节方面的进展源于单细胞荧光、膜片钳及分子生物学方法的应用。这些技术允许在细胞水平研究离子转运及其在亚细胞和分子水平的调节。这篇编辑综述聚焦于近期及新出现的观察结果，并尝试将它们整合到细胞钙转运模型中。
