title: Adverse effects of tempol on hidrosaline balance in rats with acute sodium overload.
abstract: We studied the effects of tempol, an oxygen radical scavenger, on hydrosaline balance in rats with acute sodium overload. Male rats with free access to water were injected with isotonic (control group) or hypertonic saline solution (0.80 mol/l NaCl) either alone (Na group) or with tempol (Na-T group). Hydrosaline balance was determined during a 90 min experimental period. Protein expressions of aquaporin 1 (AQP1), aquaporin 2 (AQP2), angiotensin II (Ang II) and endothelial nitric oxide synthase (eNOS) were measured in renal tissue. Water intake, creatinine clearance, diuresis and natriuresis increased in the Na group. Under conditions of sodium overload, tempol increased plasma sodium and protein levels and increased diuresis, natriuresis and sodium excretion. Tempol also decreased water intake without affecting creatinine clearance. AQP1 and eNOS were increased and Ang II decreased in the renal cortex of the Na group, whereas AQP2 was increased in the renal medulla. Nonglycosylated AQP1 and eNOS were increased further in the renal cortex of the Na-T group, whereas AQP2 was decreased in the renal medulla and was localized mainly in the cell membrane. Moreover, p47-phox immunostaining was increased in the hypothalamus of Na group, and this increase was prevented by tempol. Our findings suggest that tempol causes hypernatremia after acute sodium overload by inhibiting the thirst mechanism and facilitating diuresis, despite increasing renal eNOS expression and natriuresis.
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: N M
authors.initials: NM
authors.lastname: Kouyoumdzian
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: Nl Rukavina
authors.initials: NR
authors.lastname: Mikusic
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: G
authors.initials: G
authors.lastname: Cao
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: M R
authors.initials: MR
authors.lastname: Choi
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: Sl Della
authors.initials: SD
authors.lastname: Penna
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: B E
authors.initials: BE
authors.lastname: Fernández
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: J E
authors.initials: JE
authors.lastname: Toblli
authors.affiliation: a Cardiological Research Institute (ININCA), Scientific and Technological Research National Council (CONICET), University of Buenos Aires , Buenos Aires , Argentina.
authors.forename: M I
authors.initials: MI
authors.lastname: Rosón
mesh_terms: D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D051398:Aquaporin 1 / Q000378:metabolism; D003497:Cyclic N-Oxides / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects*; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000633:toxicity*; D013113:Spin Labels
chemical_list: D000975:Antioxidants; D003497:Cyclic N-Oxides; D013113:Spin Labels; D000804:Angiotensin II; D051398:Aquaporin 1; D012964:Sodium; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; C001803:tempol
keywords: angiotensins; aquaporins; endothelial nitric oxide synthase; hidrosaline; kidney; rat; sodium; tempol; thirst