Magnesium modulates parathyroid hormone secretion and upregulates parathyroid receptor expression at moderately low calcium concentration

Nephrol Dial Transplant. 2014 Feb;29(2):282-9. doi: 10.1093/ndt/gft400. Epub 2013 Oct 8.


Background: The interest on magnesium (Mg) has grown since clinical studies have shown the efficacy of Mg-containing phosphate binders. However, some concern has arisen for the potential effect of increased serum Mg on parathyroid hormone (PTH) secretion. Our objective was to evaluate the direct effect of Mg in the regulation of the parathyroid function; specifically, PTH secretion and the expression of parathyroid cell receptors: CaR, the vitamin D receptor (VDR) and FGFR1/Klotho.

Methods: The work was performed in vitro by incubating intact rat parathyroid glands in different calcium (Ca) and Mg concentrations.

Results: Increasing Mg concentrations from 0.5 to 2 mM produced a left shift of PTH-Ca curves. With Mg 5 mM, the secretory response was practically abolished. Mg was able to reduce PTH only if parathyroid glands were exposed to moderately low Ca concentrations; with normal-high Ca concentrations, the effect of Mg on PTH inhibition was minor or absent. After 6-h incubation at a Ca concentration of 1.0 mM, the expression of parathyroid CaR, VDR, FGFR1 and Klotho (at mRNA and protein levels) was increased with a Mg concentration of 2.0 when compared with 0.5 mM.

Conclusions: Mg reduces PTH secretion mainly when a moderate low calcium concentration is present; Mg also modulates parathyroid glands function through upregulation of the key cellular receptors CaR, VDR and FGF23/Klotho system.

Keywords: PTH; calcium-sensing receptor; magnesium; parathyroid glands; vitamin D receptor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / blood
  • Calcium / pharmacology*
  • Cells, Cultured
  • Disease Models, Animal
  • Gene Expression
  • Immunohistochemistry
  • Magnesium Compounds / pharmacology*
  • Parathyroid Glands / drug effects*
  • Parathyroid Glands / metabolism
  • Parathyroid Hormone / metabolism*
  • Phosphates / pharmacology*
  • RNA, Messenger / genetics
  • Rats
  • Rats, Wistar
  • Real-Time Polymerase Chain Reaction
  • Receptor, Fibroblast Growth Factor, Type 1 / genetics
  • Receptor, Fibroblast Growth Factor, Type 1 / metabolism
  • Receptor, Parathyroid Hormone, Type 1 / genetics
  • Receptor, Parathyroid Hormone, Type 1 / metabolism*
  • Receptors, Calcitriol / genetics
  • Receptors, Calcitriol / metabolism
  • Receptors, Calcium-Sensing / genetics
  • Receptors, Calcium-Sensing / metabolism
  • Up-Regulation


  • Magnesium Compounds
  • Parathyroid Hormone
  • Phosphates
  • RNA, Messenger
  • Receptor, Parathyroid Hormone, Type 1
  • Receptors, Calcitriol
  • Receptors, Calcium-Sensing
  • magnesium phosphate
  • Fgfr1 protein, rat
  • Receptor, Fibroblast Growth Factor, Type 1
  • Calcium