Increased Sodium-Lithium Countertransport in Red Cells of Patients with Essential Hypertension

Abstract

This paper describes experiments showing that one of the pathways of sodium transport across the red-cell membrane, sodium-lithium countertransport, is faster in patients with essential hypertension than in control subjects. This transport system accepts only sodium or lithium and is not inhibited by ouabain. The maximum rate of transport shows inherited differences. The mean maximum rate of sodium-lithium countertransport was found to be 0.55 +/- 0.02 (mean +/- S.E.M.) mmol (liter of red cells X hour)(-1) in a group of 36 patients with essential hypertension and 0.24 +/- 0.02 in 26 control subjects (P less than 0.001). The first-degree relatives of eight patients with essential hypertension and 10 control subjects had mean maximum rates of sodium-lithium countertransport of 0.54 +/- 0.05 and 0.23 +/- 0.02, respectively. Five patients with secondary hypertension had normal mean maximum rates of sodium-lithium countertransport. The relation between heritability of red-cell sodium-lithium countertransport and essential hypertension should be investigated further.

Increased red cell sodium-lithium countertransport and lymphocyte cytosolic calcium are separate phenotypes in patients with essential hypertension

“…The method for measurement used in these studies was previously described by Canessa. 1,5 Lymphocyte cytosolic Ca 2+ measurement Human lymphocytes were isolated from whole blood as previously described. 12 Steady-state levels of cytosolic calcium (Ca cyt ) were determined using the fluorescent probe, fura-2.…”

“…One of the best-characterised intermediate phenotypes in this regard is increased activity of sodium-lithium countertransport (SLC) in red blood cells. 1 The presence of this ion transport abnormality is also a phenotypic marker for risk of developing hypertension. 2,3 0.001).…”

Leucocyte Na+/H+ antiport activity in Type 1 (insulin-dependent) diabetic patients with nephropathy

“…The erythrocyte Na +/Li + countertransport activity has been shown to be raised in essential hypertension [8] and in Type 1 diabetic patients with nephropathy [6,9]. Also, family studies have established that this countertransport is strongly genetically determined [10].…”

Effects of lipids in patients with familial hypercholesterolaemia on the kinetics of the sodium-lithium countertransporter

“…[1][2][3][4][5][6][7][8][9] However, our data do not show any relationship of SLC kinetic parameters with markers of insulin resistance. This relationship has been described as being absent in other normotensive populations.…”

“…1 Associations have been demonstrated with non-insulin dependent diabetes mellitus, 2 essential hypertension, [3][4][5] and risk of coronary artery disease. [6][7][8] The activity of SLC can be resolved into kinetic components of maximal turnover velocity (V max ) and substrate affinity (K m ).…”