Parathyroid hormone and the regulation of renal tubular calcium transport.

PURPOSE OF REVIEW: Renal tubule excretion of calcium is carefully and complexly regulated. At the center of this process, parathyroid hormone (PTH) is the chief regulator of renal calcium reabsorption. This review outlines our current understanding of PTH's effects on renal tubular calcium transport, focusing on the more recent discoveries beyond its direct regulation of epithelial Ca channel transient receptor potential vanilloid 5 (TRPV5) and looking at its interaction with sodium transport and the hormones fibroblast growth factor 23 (FGF23) and klotho.

RECENT FINDINGS: PTH affects not only TRPV5 directly but other intracellular calcium transport proteins as well. In addition, PTH alters sodium transport that indirectly leads to enhanced TRPV5 activity. FGF23 and klotho have their own effects on TRPV5 as well as effects on PTH secretion.

SUMMARY: These discoveries and the interactions between these hormones have direct effects on our understanding of nephrolithiasis and have implications in the development of bone mineral disease in chronic kidney disease and may provide future treatment options.