INVESTIGADORES
CHOI Marcelo Roberto
congresos y reuniones científicas
Título:
Intrarenal renin angiotensin system components in response to tempol in rats fed with a high salt diet
Autor/es:
KOUYOUMDZIAN NM; RUKAVINA MIKUSIC NL; CAO G; DELLA PENNA SL; CHOI MR; GORZALCZANY S; FERNÁNDEZ BE; TOBLLI JE; ROSON MI
Lugar:
Mar del Plata
Reunión:
Congreso; LXI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2016
Institución organizadora:
Sociedad Argentina de Investigación Clínica (SAIC)
Resumen:
AIM: The aim of this study was to determine whether the inhibitionof oxidative stress is able to normalize arterial pressure and the disbalance betweenantagonist components of the renal renin-angiotensin system (RAS) in rats fedhigh diet salt.METHODS: Sprague-Dawley rats were fed with 8% NaCl (high-salt, HS) or 0.4% NaCl(normal-salt, NS) diet for 3 weeks, with or without tempol (T) (1mM, indrinking water). Mean arterial pressure (MAP), glomerular filtration rate(GFR), and urinary sodium excretion (UVNa) were measured.Angiotensin II (Ang II), Angiotensin 1-7 (Ang 1-7), Angiotensin Converting Enzyme2 (ACE2), Mas Receptor (MasR), Angiotensin Type 1 Receptor (AT1R) and AngiotensinType 2 Receptor (AT2R) expression were evaluated in renal tissues byimmunohistochemistry. Immunostaining wasevaluated by Image Pro Plus software analysis and expressed as integratedoptical density (IOD) ± SEM in renal tissue.RESULTS: In HS group increased MAP (NS: 92±3 vs HS: 108±3, (p< 0.05), Ang II (NS: 1404±197 vs HS: 3424±146, p<0.01) and AT1R and decreased ACE-2 expressions (NS: 642±49 vs HS: 179±23, p<0.01).Antioxidant supplementationwith T in HS group, increased natriuresis and GFR, prevented changes in bloodpressure and the imbalance of renal RAS components: decreasedexpressions of Ang II (HS: 3424±146 vs HS-T: 1889±187,p<0.01) and AT1R, and increased expressions of AT2 (HS: 236±7vs HS-T: 331±13, p<0.01), ACE2 (HS: 179±23 vs HS-T: 567±29, p<0.01),Ang (1-7) (HS: 686±41 vs HS-T: 5313±475,p<0.01) and MasR.CONCLUSION:These findings suggest that aHS diet alters the physiological balance between opposing hypertensive vsantihypertensive components of the renal RAS, favouring the renal expression ofAng II and decreasing Ang II degradation by down-regulation of ACE2. Inhibitionof oxidative stress by T prevents this imbalance and decreased blood pressurelevels.