Increased activity of the Na(+)-dependent Cl(-)-HCO3- anion exchanger in erythrocytes of patients with essential hypertension.
OBJECTIVE
To study the activity of the Na(+)-dependent Cl(-)-HCO3- anion exchanger in erythrocytes of patients with essential hypertension.


METHODS
The study was performed in cells from 48 untreated essential hypertensive patients and 30 normotensive controls with similar age- and sex- distribution.


METHODS
The activity of the Na(+)-dependent anion exchanger was determined by measuring the 4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS) sensitive Li+ influx in fresh cells incubated into a medium containing Li2CO3.


RESULTS
The DIDS-sensitive Li+ influx was higher in hypertensives than controls. With the 100% confidence (upper) limit of the normotensive population as a cut-off point, a subgroup of 11 hypertensives had an abnormally high activity of the Na(+)-dependent Cl(-)-HCO3- anion exchanger. Compared with patients with normal exchanger activity, patients with increased exchanger activity were characterized by the following: higher frequency of family history of hypertension; lower serum high-density lipoprotein cholesterol levels and higher plasma aldosterone concentrations. After multiple regression analysis, the DIDS-sensitive Li+ influx was inversely correlated with high-density lipoprotein cholesterol levels.


CONCLUSIONS
These results show the presence of a new abnormality of erythrocyte Na+ transport in essential hypertension--increased activity of the Na(+)-dependent Cl(-)-HCO3- anion exchanger. In addition, our findings suggest that from the clinical point of view, patients with this transport abnormality represent a particular subset of essential hypertensives.
Díez
J
J
Department of Medicine, School of Medicine, University of Navarra, Spain.
Arrázola
A
A
Castiella
J
J
Iñigo
B
B
Cía
P
P
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001692:Biological Transport / Q000187:drug effects; D002352:Carrier Proteins / Q000097:blood*; D027963:Chloride-Bicarbonate Antiporters; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000453:epidemiology; D008094:Lithium / Q000097:blood; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012964:Sodium / Q000097:blood*
D002352:Carrier Proteins; D027963:Chloride-Bicarbonate Antiporters; D012856:4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid; D008094:Lithium; D012964:Sodium; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid