Arnold Felsenfeld1, Mariano Rodriguez, Burton Levine. 1. Department of Medicine, VA Greater Los Angeles Healthcare System and the David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
Abstract
PURPOSE OF REVIEW: Regulation of calcium homeostasis during a lifetime is a complex process reflecting a balance among intestinal calcium absorption, bone calcium influx and efflux, and renal calcium excretion. Perturbations can result in hypocalcemia or hypercalcemia and adaptations in calcium handling must occur during growth and aging. RECENT FINDINGS: Study of the calcium sensing receptor in the thick ascending limb of Henle and TRPV5 in the distal tubule continues to provide insights into regulation of renal calcium excretion. Hypercalcemia-induced secretion of calcitonin via activation of the calcium-sensing receptor may protect against the development of hypercalcemia. A calcilytic was shown to increase serum calcium by decreasing renal calcium excretion. Ezrin, a cross-linking protein important for renal phosphate handling, is also involved in the regulation of intestinal calcium absorption. Increased 1,25-hydroxyvitamin D (1,25D) values were shown to protect against the development of hypocalcemia by increasing calcium efflux and decreasing calcium influx in bone. Finally, fibroblast growth factor 23 stimulation, which should result in suppression of 1,25D, was shown to be prevented in a model of vitamin D deficiency in which maintenance of 1,25D is important in minimizing hypocalcemia. SUMMARY: Recent information has provided new insights on how intestinal, bone and renal mechanisms are regulated to maintain calcium homeostasis.
PURPOSE OF REVIEW: Regulation of calcium homeostasis during a lifetime is a complex process reflecting a balance among intestinal calcium absorption, bone calcium influx and efflux, and renal calcium excretion. Perturbations can result in hypocalcemia or hypercalcemia and adaptations in calcium handling must occur during growth and aging. RECENT FINDINGS: Study of the calcium sensing receptor in the thick ascending limb of Henle and TRPV5 in the distal tubule continues to provide insights into regulation of renal calcium excretion. Hypercalcemia-induced secretion of calcitonin via activation of the calcium-sensing receptor may protect against the development of hypercalcemia. A calcilytic was shown to increase serum calcium by decreasing renal calcium excretion. Ezrin, a cross-linking protein important for renal phosphate handling, is also involved in the regulation of intestinal calcium absorption. Increased 1,25-hydroxyvitamin D (1,25D) values were shown to protect against the development of hypocalcemia by increasing calcium efflux and decreasing calcium influx in bone. Finally, fibroblast growth factor 23 stimulation, which should result in suppression of 1,25D, was shown to be prevented in a model of vitamin D deficiency in which maintenance of 1,25D is important in minimizing hypocalcemia. SUMMARY: Recent information has provided new insights on how intestinal, bone and renal mechanisms are regulated to maintain calcium homeostasis.
Authors: Mark K van Goor; Sjoerd Verkaart; Teunis J van Dam; Martijn A Huynen; Jenny van der Wijst Journal: Pflugers Arch Date: 2017-05-22 Impact factor: 3.657
Authors: Cristian Rodelo-Haad; Rafael Santamaria; Juan R Muñoz-Castañeda; M Victoria Pendón-Ruiz de Mier; Alejandro Martin-Malo; Mariano Rodriguez Journal: Toxins (Basel) Date: 2019-03-22 Impact factor: 4.546
Authors: Jie Gu; Shuya Dai; Yanmin Liu; Haitao Liu; Yao Zhang; Xingqi Ji; Feng Yu; Yang Zhou; Liang Chen; William Ka Fai Tse; Chris Kong Chu Wong; Binghai Chen; Haifeng Shi Journal: Sci Rep Date: 2018-01-18 Impact factor: 4.379