Acute sodium overload produces renal tubulointerstitial inflammation in normal rats

The aim of the present study was to determine whether acute sodium overload could trigger an inflammatory reaction in the tubulointerstitial (TI) compartment in normal rats. Four groups of Sprague-Dawley rats received increasing NaCl concentrations by intravenous infusion. Control (C): Na + 0.15M; G1: Na+ 0.5M; G2: Na+ 1.0M; and G3: Na+ 1.5M. Creatinine clearance, mean arterial pressure (MAP), renal blood flow (RBF), and sodium fractional excretion were determined. Transforming growth factor β1 (TGF-β1), α-smooth muscle actin (α-SMA), RANTES, transcription factor nuclear factor-kappa B (NF-κB), and angiotensin II (ANG II) were evaluated in kidneys by immunohistochemistry. Animals with NaCl overload showed normal glomerular function without MAP and RBF modifications and exhibited a concentration-dependent natriuretic response. Plasmatic sodium increased in G2 (P G2>C group. These results suggest that an acute sodium overload is able 'per se' to initiate TI endothelial inflammatory reaction (glomerular and peritubular) and incipient fibrosis in normal rats, independently of hemodynamic modifications. Furthermore, these findings are consistent with the possibility that activation of NF-κB and local ANG II may be involved in the pathway of this inflammatory process.Fil: Roson, Maria Ines. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cavallero, Carmen Susana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Della Penna, Silvana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Cao, Gabriel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Hospital Alemán; ArgentinaFil: Gorzalczany, Susana Beatriz. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Pandolfo, Marcela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Kuprewicz, A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Canessa, O.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: Toblli, Jorge Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Hospital Alemán; ArgentinaFil: Fernandez, Belisario Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentin