F006: Inverse membranous calcium and magnesium correlation in a subgroup of essential hypertensives

Abstract

A cellular Ca⁺⁺-Mg⁺⁺ antagonism seems to be involved in the pathogenesis of primary hypertension. Therefore, plasma and membranous and intracellular Ca⁺⁺ and Mg⁺⁺ contents were determined in 30 normotensive healthy subjects (NT) and 30 untreated essential hypertensives (EH) by atomic absorption spectroscopy and as a membranous reference membrane protein content was determined according to Bradford's method. There was no significant difference in plasma Ca⁺⁺ (NT: 2.52 ± 0.11 vs. EH: 2.66 ± 0.14 mmol/l) and Mg⁺⁺ contents (NT: 0.89 ± 0.14 vs. EH: 0.85 ± 0.10 mmol/l). In NT membrane Ca⁺⁺ was 0.81 ± 0.32 vs. 2.46 ± 0.26 μmol/g membranous protein in the EH group (means ± SD, p < 0.01). In EH membranous Mg⁺⁺ content was significantly decreased as compared to controls (0.28 ± 0.04 vs. 0.53 ± 0.08 mmol/g membrane protein (p < 0.01). Additionally, red blood cell Ca⁺⁺ and Mg⁺⁺ concentrations were not found significantly different in the two studied groups (NT: 1.96 ± 0.24; 1.78 ± 0.13 vs. EH: 2.02 ± 0.22; 1.61 ± 0.21 mmol/l). The Ca⁺⁺/Mg⁺⁺ ratio in red blood cell membranes was significantly increased in essential hypertensives as compared to healthy subjects, indicating an atherogenic risk factor (p < 0.01) and additionally correlated to blood pressure values (r = 0.52, p < 0.01). A membranous Ca⁺⁺-Mg⁺⁺ antagonism (r = −0.61, p < 0.01) seems to be involved in the pathogenesis of primary hypertension. This antagonism may be due to a defect in transmembrane transport.

Magnesium, calcium, membranes, hypertension