title: Adenosine, type 1 receptors: role in proximal tubule Na+ reabsorption.
abstract: Adenosine type 1 receptor (A1 -AR) antagonists induce diuresis and natriuresis in experimental animals and humans. Much of this effect is due to inhibition of A1 -ARs in the proximal tubule, which is responsible for 60-70% of the reabsorption of filtered Na(+) and fluid. Intratubular application of receptor antagonists indicates that A1 -AR mediates a portion of Na(+) uptake in PT and PT cells, via multiple transport systems, including Na(+) /H(+) exchanger-3 (NHE3), Na(+) /PO4(-) co-transporter and Na(+) -dependent glucose transporter, SGLT. Renal microperfusion and recollection studies have shown that fluid reabsorption is reduced by A1 -AR antagonists and is lower in A1 -AR KO mice, compared to WT mice. Absolute proximal reabsorption (APR) measured by free-flow micropuncture is equivocal, with studies that show either lower APR or similar APR in A1 -AR KO mice, compared to WT mice. Inhibition of A1 -ARs lowers elevated blood pressure in models of salt-sensitive hypertension, partially due to their effects in the proximal tubule.
authors.affiliation: Department of Medicine, Georgetown University, Washington, DC, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Welch
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D065608:Renal Reabsorption / Q000235:genetics / Q000502:physiology*; D012965:Sodium Chloride / Q000378:metabolism*; D012982:Sodium, Dietary / Q000378:metabolism*
chemical_list: D012982:Sodium, Dietary; D012965:Sodium Chloride; D000241:Adenosine
keywords: adenosine receptors; proximal tubule; sodium transport