title: The effect of calcium and magnesium ions on calcium pyrophosphate crystal formation in aqueous solutions.
abstract: Calcium pyrophosphate crystal formation has been associated clinically with hypercalcemic states (hyperparathyroidism) and hypomagnesemia. We studied aqueous solutions at pH 7.4, 37 degrees C, [Na+] = 140 nM over a range of calcium chloride/magnesium chloride/sodium pyrophosphate concentrations to determine the effect of calcium and magnesium ions on crystal formation. We found that CPPD(T) and CPPD(M) could form under different ionic conditions. Low [Mg++] and [PPi] favoured CPPD(T) whereas higher [Mg++] and [PPi] favoured CPPD(M). At [Mg++] = 1.0 mM a calcium magnesium pyrophosphate crystal phase designated CMPP2 formed. As [Mg++] affects the crystal phase formed more than equimolar [Ca++], we conclude that ionic magnesium deficiency may be a clinically important determinant in calcium pyrophosphate dihydrate crystal formation.
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002131:Calcium Pyrophosphate; D055598:Chemical Phenomena; D002621:Chemistry; D003460:Crystallization; D011756:Diphosphates; D008274:Magnesium / Q000494:pharmacology*; D012996:Solutions; D013997:Time Factors; D014867:Water
chemical_list: D011756:Diphosphates; D012996:Solutions; D014867:Water; D008274:Magnesium; D002118:Calcium; D002131:Calcium Pyrophosphate