Purpose Of Review: 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.
Recent Findings: 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.
Summary: 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.
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http://dx.doi.org/10.1097/MNH.0b013e3282b974a6 | DOI Listing |
J Pediatr Urol
December 2024
Department of Pediatrics, Faculty of Medicine, Cairo University, Cairo, Egypt. Electronic address:
Backgrounds: The pathophysiology of nephrolithiasis is complex, influenced by both environmental and genetic factors. Calcium is the most prevalent metabolite present in the stone matrix. Stimulating the basolateral calcium sensing receptor (CASR) in the renal tubules leads to an increase in claudin-14 expression, reducing paracellular calcium permeability and increasing urinary Ca excretion.
View Article and Find Full Text PDFJ Dairy Sci
January 2025
Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, 53701. Electronic address:
Inducing a transient state of hypocalcemia prepartum mobilizes stored calcium (Ca) before the abrupt demand for Ca at parturition thus more tightly regulating postpartum hypocalcemia. Prepartum transient hypocalcemia can be achieved through intravenous infusions of either the precursor to serotonin, 5-hydroxy-tryptophan (5HTP) or a Ca chelating agent, ethylene-glycol-tetraacetic acid (EGTA). This study aimed to compare the ability of 5HTP and EGTA treatments to prevent postpartum hypocalcemia.
View Article and Find Full Text PDFFEBS Lett
January 2025
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
Soluble, circulating Klotho (sKlotho) is essential for normal health and renal function. sKlotho is shed from the renal distal convoluted tubule (DCT), its primary source, via enzymatic cleavage. However, the physiologic mechanisms that control sKlotho production, trafficking, and shedding are not fully defined.
View Article and Find Full Text PDFBull Exp Biol Med
December 2024
School of Basic Medicine, Gannan Medical University, Ganzhou, China.
Extracellular Ca is the first ligand that has been confirmed to function by activating the calcium-sensing receptor (CaSR), a member of G-protein coupled receptors. CaSR controls not only calcium homeostasis, but also plays a pivotal role in many cellular processes such as cell proliferation and apoptosis; moreover, it is implicated in the development of cardiovascular diseases. TGF-β/Smads signaling pathway is a classical pathway of renal fibrosis.
View Article and Find Full Text PDFInflamm Bowel Dis
January 2025
Department of Gastroenterology, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China.
Background: Patients with ulcerative colitis (UC) exhibit abnormal amino acid (AA) metabolism. Taste receptors play a crucial role in the detection of intestinal AAs. Nevertheless, it remains unclear whether UC patients exhibit abnormal expression of these receptors in the colon.
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