Role of the calcium-sensing receptor in regulating calcium transport in the thick ascending limb
Related Experiment Video
Updated: Jun 10, 2026

Monitoring ER/SR Calcium Release with the Targeted Ca2+ Sensor CatchER+
Published on: May 19, 2017
Milos Bogdanovic1, Henrik Dimke1,2
1Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark.
Purpose Of Review:
The calcium-sensing receptor (CASR) is a principal regulator of calcium balance. In the kidney, it directly modulates calcium reabsorption in the thick ascending limb (TAL). This review focuses on the CASR in TAL, its role in regulating renal calcium transport and hence systemic calcium homeostasis.
Recent Findings:
Functional studies demonstrate that hypercalcemia-induced increases in urinary calcium excretion depend on renal CASR signaling, primarily through reduced paracellular calcium permeability in the TAL. Loss of the renal Casr in mice impairs urinary calcium excretion in conditions of hypercalcemia. Microperfusion shows reduced calcium permeability in cortical TALs from hypercalcemic wildtype mice, a response absent in Casr -deficient mice. CASR activation upregulates claudin-14 (CLDN14), a tight junction protein that selectively blocks paracellular divalent cation reabsorption. Single cell RNA-seq and protein expression studies reveal substantial TAL cell-type heterogeneity, identifying distinct transporter- and claudin- expressing populations. This mosaic organization of paracellular pathways provides a framework for understanding TAL-specific regulation of renal calcium handling.
Summary:
The TAL CASR acts as a sensor of blood calcium and adjusts paracellular transport by reducing tight junction permeability. While protective against hypercalcemia, sustained activation may promote hypercalciuria and nephrolithiasis.
More Related Videos
Related Concept Videos
Feedback Regulation of Calcium Concentration
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Reabsorption and Secretion in the Loop of Henle
Reabsorption and Secretion in the DCT and Collecting Duct
The distal part of the DCT, along with the...
Skeleton and Calcium Homeostasis
Physiology of the Genitourinary System II: Tubular Reabsorption and Secretion
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...

