[Na+, K+, Cl-]-cotransport function and dysfunction in different forms of primary hypertension.
Am J Hypertens
; 1(3 Pt 3): 60S-63S, 1988 Jul.
Article
em En
| MEDLINE
| ID: mdl-3415811
ABSTRACT
We investigated the effect of an increase in cell Na+ content on outward and inward unidirectional fluxes catalyzed by the [Na+, K+, Cl-]-cotransport system in human erythrocytes (incubated in Li-Rb media). Erythrocytes with low Na+ content exhibited an uncoupled K+ efflux. The increase in cell Na+ content resulted in a more marked stimulation of outward Na+, K+ than of inward Li+, Rb+ cotransport fluxes (with stoichiometries not very different from one-to-one). These results suggest that in human erythrocytes and in nonepithelial cells with small but outwardly directed electrochemical Cl- gradients, the [Na+, K+, Cl-]-cotransport system may behave as a "second pump" by using the extra energy supplied by an additional net [K+, Cl-] efflux. The [Na+, K+, Cl-]-cotransport system (of vascular cells and/or noradrenergic endings) may play two different roles in primary hypertension (a) "defective second pump" in some essential hypertensive patients with decreased cotransport affinity for internal Na+ and (b) "compensatory second pump" in other forms of primary hypertension where abnormalities in the Na+, K+ pump or in other ion transport systems may predispose the cell to a defective extrusion of excess cell Na+ content.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas de Transporte
/
Hipertensão
Limite:
Humans
Idioma:
En
Revista:
Am J Hypertens
Assunto da revista:
ANGIOLOGIA
Ano de publicação:
1988
Tipo de documento:
Article
País de afiliação:
França