This Month’s Highlights

[摘要] 1,25(OH)2 vitamin D3 plays a central role in regulating kidney and intestinal calcium absorption via channels that have recently been identified as members of the Vth subfamily of the transient receptor potential cation channel family (TRPV5). Renkema et al. used knockout mouse models to deftly explore the physiologic role of these channels. If the kidney form expressed in the distal tubule was knocked out, circulating 1,25(OH)2 vitamin D3 increased and maintained calcium balance by enhancing intestinal calcium uptake. If these animals were crossed with mice that were 1α-hydroxylase–deficient, the compensatory increase in active vitamin D3 did not occur, and these mice developed hypocalcemia, hyperparathyroidism, and rickets. These studies describe interactions between intestinal, kidney, and parathyroid functions, and provide solid evidence for the localization and physiologic role of the TRPV5 channels, and the underlying importance of 1,25(OH)2 vitamin D3 in coordinating their activity. See Renkema et al., pages 3188–3195.

[学科分类] 泌尿医学

[关键词] Bone marrow necrosis;Sickle cell disease;Hyperhemolysis syndrome