title: Detection of a circulating inhibitor of the Na(+)-K(+)-Cl(-) cotransport system in plasma and urine after high salt intake.
abstract: The aim of the study was to detect the presence of an endogenous Na(+)-K(+)-Cl- cotransport inhibitor factor in plasma and urine from salt-loaded subjects. Twenty-six essential hypertensive patients (13 men, 13 women) and 6 normotensive controls (2 men, 4 women) received a diet containing 260 mmol/day of NaCl tablets for 7 days. Human erythrocytes from healthy blood donors (using bumetanide-stimulated Li+ efflux) were used to test the inhibition of Na(+)-K(+)-Cl- cotransport by different plasma and urine concentrations collected the last day of the salt-loaded period. The addition of plasma and urine from salt-loaded subjects significantly inhibited erythrocyte Na(+)-K(+)-Cl- cotransport (P < .001). No differences were observed between hypertensive patients and normotensive controls. These results provide evidence of an Na(+)-K(+)-Cl- cotransport inhibitor factor in plasma and urine from salt-loaded humans, in concordance with previous reports in salt-loaded rats.
authors.affiliation: Department of General Internal Medicine, Hospital Clínico, Barcelona, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Parés
authors.forename: A
authors.initials: A
authors.lastname: de la Sierra
authors.forename: A
authors.initials: A
authors.lastname: Coca
authors.forename: M M
authors.initials: MM
authors.lastname: Lluch
authors.forename: A
authors.initials: A
authors.lastname: Urbano-Márquez
authors.forename: R
authors.initials: R
authors.lastname: Garay
mesh_terms: D000328:Adult; D000368:Aged; D001769:Blood / Q000378:metabolism*; D001790:Blood Physiological Phenomena; D002034:Bumetanide / Q000494:pharmacology; D002352:Carrier Proteins / Q000037:antagonists & inhibitors* / Q000097:blood / Q000652:urine; D004039:Diet, Sodium-Restricted; D004912:Erythrocytes / Q000378:metabolism; D005260:Female; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000652:urine; D008094:Lithium / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D028021:Sodium-Potassium-Chloride Symporters; D014556:Urine / Q000737:chemistry* / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D028021:Sodium-Potassium-Chloride Symporters; D002034:Bumetanide; D008094:Lithium