Erythrocyte Na+-H+ exchanger and Na+-Li+ countertransport activity in primary aldosteronism |
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Authors: | P DELVA C PASTORI M DEGAN G MONTESI A BASSI A LECHI |
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Institution: | Institute of Internal Medicine;*Clinical Chemistry, University of Verona, Policlinico Borgo Roma, Verona, Italy |
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Abstract: | Abstract. Several authors have described increased Na-H exchanger activity in essential hypertension but no data are available in secondary forms of hypertension such as primary aldosteronism. We measured Na-H exchanger kinetics together with Na-Li countertransport V max in the erythrocytes of eight patients with primary aldosteronism and in 15 normotensive control subjects. Plasma aldosterone, plasma renin and plasma potassium were also evaluated. Na-H exchanger V max appear to be increased in patients with primary aldosteronism and Hill's n , an index of co-operativity amongst intracellular proton binding sites, was significantly lower in patients than in controls. No statistically significant differences were found between affinity for intracellular protons (K50%) and for Na-Li countertransport V max between the two groups studied. We were unable to find any correlations between Na-H exchanger V max and Na-Li countertransport V max in the two groups considered as a whole. From the present data Na-H exchanger overactivity would not appear to be a specific feature of essential hypertension but seems to be characteristic in patients with primary aldosteronism. |
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Keywords: | Hypertension Na-H antiport Na-Li countertransport Primary aldosteronism |
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