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Twenty to fifty percent of the ouabain-insensitive Na+ and K+ fluxes in human red blood cells are mediated by Cl(-) -dependent coupled transport (cotransport). In this paper we report on the effect of the sulfhydryl group reagent N-ethylmaleimide (NEM) on Cl(-) -dependent ouabain-insensitive Na+ and K+ fluxes in human red blood cells. We found that NEM(More)
A new and simple laboratory test for measuring net Na+ and K+ fluxes in Na+-loaded/K+-depleted human erythrocytes was developed and applied to hypertension. Moderate essential hypertension (10 patients) was characterised by a constant increase in net K+ influx, possibly related to higher Na+, K+-pump activity. In more severe cases (8 patients) net Na+(More)
The Na+ and K+ electrochemical gradients across cell membranes are believed to be maintained by the action of a Na+, K+-pump. In human erythrocytes this pump exchanges internal Na+ for external K+ in approximately a 1.5 ratio. Thus, when Na+-loaded/K+-depleted erythrocytes are incubated in physiological conditions they tend to recover their original low(More)
Five red blood cell cation transport systems (RBCTS), together with blood lead level and blood pressure, were measured in 129 male adult subjects who were not occupationally exposed to lead or subsequent to a course of treatment for hypertension. Blood lead was positively related with systolic blood pressure, and to a lesser degree with diastolic blood(More)
The urinary isoflavonoid genistein inhibits membrane Na-K-Cl cotransporters at similar concentrations as furosemide, but the significance of this action is unknown. Genistein was therefore investigated in rats for its potential salidiuretic actions. In the isolated, perfused rat kidney, genistein induced a maximal salidiuretic action similar to that of(More)
In crude rat cardiac membrane preparations, [3H]dihydroergocryptine (3H-DHE) appears to bind to two classes of sites with limited capacity, differing in their specificities and their affinities. The first class of binding sites interacts preferentially with the postsynaptic alpha-adrenoceptor blocker ARC239, as can be expected for postsynaptic(More)
We examined the kinetic properties of the interactions between inner and outer cation sites of the Na-Li countertransport system in human red blood cells. Li-stimulated Na efflux [V(Na)] was measured as a function of external Li [(Li)o] and internal Na [(Na)i] contents. At each (Li)o, a Hanes plot of (Na)i/V(Na) vs. (Na)i allowed us to calculate the(More)
RATIONALE Cyamemazine is a neuroleptic compound which possesses anxiolytic properties in humans. On the other hand, 5-HT3- and 5-HT2C-receptors have been implicated in anxiety disorders and a previous binding study has shown that cyamemazine possesses high affinity for both serotonin receptor types. OBJECTIVE The present study was undertaken to establish(More)
Different Li, Na and K transport pathways were assessed in erythrocytes from manic-depressive patients. No alteration in the Li-Na countertransport, Na,K cotransport or passive permeabilities was observed in either unipolar or bipolar manic-depressive patients. In addition, acute or chronic lithium treatment did not alter the maximal velocity of either the(More)
We investigated the effects of PAF-acether and its specific antagonist BN 52021 on Na+ and K+ transport systems in human red cells and mouse macrophages. PAF-acether and BN 52021 exhibited specific and opposite effects on a Cs+-stimulated, K+ efflux in human red cells. PAF-acether increased and BN 52021 decreased the apparent dissociation constant for(More)