Alterations in calcium and magnesium content of red cell membranes in patients with primary hypertension

A cellular calcium-magnesium antagonism seems to be involved in the pathoge nesis of primary hypertension. Total plasma, intracellular, and membranous calcium (Ca) and magnesium (Mg) contents were determined in 39 untreated pa tients with essential hypertension (EH) and 40 normotensive healthy subject s (NT). Membranous and intracellular measurements were performed in erythro cytes. Ca and Mg contents were measured by atomic absorption spectroscopy a nd membrane protein was determined according to Bradford's method as a memb ranous reference. There was no significant difference in plasma Ca (NT: 2.6 0 +/- 0.15 v EH: 2.64 +/- 0.17 mmol/L) and ME concentrations (NT: 0.83 +/- 0.12 v EH: 0.87 +/- 0.14 mmol/L) in the studied groups. Intracellular Mg (N T: 1.72 +/- 0.15 mmol/L v EH: 1.64 +/- 0.19 mmol/L) and Ca (NT: 2.06 +/- 0. 20 mmol/L v EH: 2.10 +/- 0.24 mmol/L) contents were also not significantly different between groups. Membrane Ca content was significantly increased i n the EH group (2.23 +/- 0.32 mu mol/g membranous protein) compared to cont rols (1.05 +/- 0.30 mu mol/l membranous protein, P < .01). On the contrary, membranous Mg content was significantly decreased compared to controls (0. 31 +/- 0.09 v 0.50 +/- 0.10 mmol/g membranous protein content, P < .01). Th e Ca/Mg ratio in membranes was significantly increased in EH as compared to healthy subjects (P < .01) and correlated to mean arterial blood pressure values (r = 0.47, P < .01). We conclude that the membranous alterations of Ca and Mg metabolism, shown by increased Ca/Mg ratio in red cell membranes of hypertensive subjects, may play a role in the pathogenesis of primary hy pertension. (C) 2001 American Journal of Hypertension, Ltd.