Magnesium stimulates renal phosphate reabsorption

摘要

magnesium (Mg~(2+)) is the second most abundant intracellular cation in vertebrates. It interacts with calcium (Ca~(2+)) and phosphate (Pi) homeostasis in different ways. Mg~(2+) activates like Ca~(2+) the Ca~(2+)-sensing receptor (CaSR) of the parathyroid glands (2). Activation of the CaSR results in decreased parathyroid hormone (PTH) secretion. Although Mg~(2+) is less potent than Ca~(2+) in stimulating the CaSR, genetic diseases caused by mutations in the CaSR gene suggest that CaSR serves as an Mg~(2+) sensor in vivo. Individuals with autosomal-dominant hypoparathyroidism (ADH) due to activating mutations of the CaSR show, besides hypercalciuric hypocalcemia, tendencies toward hypomagnesemia and hyperphosphatemia (10). Heterozygous inactivating mutations of the CaSR cause familial hypocalciuric hypercalcemia (FHH), which is characterized by hypocalciuric hypercalcemia often associated with hypomagnesiuric hypermagnesemia (26).