DECREASED CELLULAR MG2- CELL MODELS FOR THE PATHOGENESIS OF PRIMARY HYPERTENSION( CONCENTRATIONS IN A SUBGROUP OF HYPERTENSIVES )

A new method to determine total Mg2+ content in lymphocytes was develo ped, offering advantages for routine measurements as compared to fluor escence methods. Intracellular Mg2+ measurements were performed in lym phocytes of 18 untreated normotensive and 19 untreated essential hyper tensive patients. Mg2+ content was referred to lymphocytic protein, wh ich was determined according to Bradford's method. Mg2+ measurements w ere performed by atomic absorption spectroscopy using a Video 12 appar atus from Thermo Electron Instrumentation Laboratory, Andover, MA, USA . The results show that in patients with essential hypertension, total intralymphocytic Mg2+ content is significantly lower (0.07 +/- 0.05 m mol/g lymphocytic protein, mean +/- s.d.) as compared to controls (0.1 1 +/- 0.04 mmol/g lymphocytic protein, mean +/- s.d., P < 0.05). Free intracellular Mg2+ content was measured in lymphocytes by the fluoresc ent indicator mag-fura-II, showing no significant difference in normot ensives and hypertensives (0.30 +/- 0.16 vs 0.38 +/- 0.17 mmol/l). In platelets free intracellular Mg2+ concentrations were not found of sig nificant difference in normotensive and hypertensive patients (0.52 +/ - 0.23 vs 0.47 +/- 0.27 mmol/l) using mag-fura-II, In plasma Mg2+ conc entrations there was no significant difference in the normotensive and hypertensive group (0.92 +/- 0.07 vs 0.88 to 0.07 mmol/l). There was no correlation between plasma, free or total cellular magnesium concen trations in each group. Furthermore this method also seems suitable fo r routine measurements of total intracellular Mg2+ concentrations in e ven larger groups of patients in comparison with fluorescent indicator measurements like mag-fura-II, Lowered total intracellular Mg2+ conce ntrations in a subgroup of primary hypertension may contribute to the development of this disorder, perhaps due to different buffering syste ms.