Plasma and Membrane Ca²⁺ and Mg²⁺ Concentrations in Normal Pregnancy and in Preeclampsia

Abstract

Objective: Changes in intracellular Ca²⁺ and Mg²⁺ concentrations seem to be involved in the pathogenesis of preeclampsia, whereas the role of cell membranes has not been studied in detail yet. To investigate the changes in Ca²⁺ and Mg²⁺ metabolism in normal pregnancy and preeclampsia, plasma and membrane Ca²⁺ and Mg²⁺ concentrations were determined in a clinical study as compared to healthy subjects. Study Design: 25 healthy female subjects, 22 untreated healthy pregnant and 20 preeclamptic women were investigated. In each patient, plasma and membrane Ca²⁺ and Mg²⁺ content were measured. Ca²⁺ and Mg²⁺ concentrations were measured by atomic absorption spectroscopy. Erythrocyte membranes were chosen for membranous Ca²⁺ and Mg²⁺ determination. Results: Plasma Mg²⁺ concentrations were significantly lowered in the healthy pregnant group and the preeclamptic group as compared to contols (p < 0.0001). In erythrocyte membranes, Mg²⁺ content was found significantly decreased in the preeclamptic women as compared to healthy subjects (p < 0.001). In plasma Ca²⁺ concentrations there was a significant decrease in the preeclamptic group as compared to controls or healthy pregnant women (p < 0.05). Membranous Ca²⁺ content was significantly increased in the preeclamptic group versus controls or healthy pregnant women (p < 0.001). Conclusion: Lowered plasma and membrane Mg²⁺ concentrations in preeclampsia may contribute to the development of hypertension in pregnancy. Additionally, a disturbed Ca²⁺ homeostasis is observed in preeclampsia.

The Role of Calcium, Magnesium, and Zinc in Pre-Eclampsia

“…This supports an association between altered calcium metabolism and pre-eclampsia. Our findings in the present study are in concurrence with the observations of Kumru et al [14], Joshi et al [34], Sukonpan and Phunpong [35], Kisters et al [39], and Kosch et al [40], although an opposite trend has also been reported [41,42]. Somehow, serum levels of calcium seem to play a part in the development of pre-eclampsia, as it has been seen that a reduction in serum calcium level causes increase in release of parathyroid hormone and renin, which in turn cause increase in intracellular calcium in vascular smooth muscle.…”

“…However, the data from these studies are not so equivocal. No alteration [2,14,37], elevation [43,44], or reduction [33][34][35]39] in plasma or serum magnesium concentration have been demonstrated in pre-eclamptic women. Similarly, no change [37,45], elevation [46,47], or decrease [14,34,48,49] in serum or plasma zinc has been reported in pre-eclamptic women as compared to normal pregnant controls.…”

Effect of Hypoxia on the Calcium and Magnesium Content, Lipid Peroxidation Level, and Ca2+-ATPase Activity of Syncytiotrophoblast Plasma Membranes from Placental Explants

“…Red blood cell ghosts were prepared with a modification of a previously described method [25]. Aliquots of BM and MVM were washed three times by centrifugation-resuspension at 47,500 ×g for 45 min.…”

Differential mRNA Expression and Glucocorticoid-Mediated Regulation of TRPM6 and TRPM7 in the Heart and Kidney throughout Murine Pregnancy and Development

“…It is important to note although estrogen is known to increase TRPM6 expression, plasma estrogen and magnesium levels are inversely related both in women of reproductive age [ 40 ] and in menopausal women[ 41 ]. Interestingly, while some studies have reported lower plasma magnesium levels in pregnancy [ 42 ], a recent longitudinal study in pregnant women reported that serum magnesium levels were similar in all three trimesters, despite the large increase in plasma estrogen that occurs in the third trimester [ 43 ]. This suggests that there are additional mechanisms contributing to the regulation of TRPM6 and magnesium homeostasis during pregnancy to maintain physiologically normal levels of magnesium despite the large hormonal changes that occur in pregnancy.…”