Impact of magnesium:calcium ratio on calcification of the aortic wall

PLoS One. 2017 Jun 1;12(6):e0178872. doi: 10.1371/journal.pone.0178872. eCollection 2017.

Abstract

Objective: An inverse relationship between serum magnesium concentration and vascular calcification has been reported following observational clinical studies. Moreover, several studies have been suggesting a protective effect of magnesium on the vascular calcification. However, the exact mechanism remains elusive, and investigators have speculated among a myriad of potential actions. The effect of magnesium on calcification of the aortic wall is yet to be investigated. In the present study, the effects of magnesium and calcium on the metabolism of extracellular PPi, the main endogenous inhibitor of vascular calcification, were investigated in the rat aorta.

Approach and results: Calcium and magnesium have antagonist effects on PPi hydrolysis in the aortic wall. Km and Ki values for PPi hydrolysis in rat aortic rings were 1.1 mmol/L magnesium and 32 μmol/L calcium, respectively, but ATP hydrolysis was not affected with calcium. Calcium deposition in the rat aortic wall dramatically increased when the magnesium concentration was increased (ratio of Mg:Ca = 1:1; 1.5 mmol/L calcium and 1.5 mmol/L magnesium) respect to low magnesium concentration (ratio Mg:Ca = 1:3, 1.5 mmol/L calcium and 0.75 mmol/L magnesium).

Conclusion: Data from observational clinical studies showing that the serum magnesium concentration is inversely correlated with vascular calcification could be reinterpreted as a compensatory regulatory mechanism that reduces both PPi hydrolysis and vascular calcification. The impact of magnesium in vascular calcification in humans could be studied in association with calcium levels, for example, as the magnesium:calcium ratio.

MeSH terms

  • Animals
  • Aorta / metabolism*
  • Aorta / pathology
  • Calcinosis*
  • Calcium / metabolism*
  • Kinetics
  • Magnesium / metabolism*
  • Rats
  • Vascular Calcification*

Substances

  • Magnesium
  • Calcium

Grant support

This study was supported by grant SAF-2014-60699-JIN from the Spanish Ministerio de Economía y Competitividad (MINECO). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.