Renal oxidative stress in hypertensive rats. Atrial natriuretic peptide chronic treatment.

LUCÍA SAVIGNANO; AGUSTINA MOLINARI; GONZALO BOUCHET; SOFÍA AGUIRRE; CAROLINA CANIFFI; MARIANA ROMERO; ANALIA TOMAT; ROSANA ELESGARAY; CRISTINA ARRANZ; MARÍA ÁNGELES COSTA

Buenos Aires, Argentina.

Workshop; International Workshop in oxidative stress and antioxidants.; 2009

The aim of the study was to investigate the effects of chronic infusion with atrial natriuretic peptide (ANP) on renal oxidative stress in spontaneously hypertensive rats (SHR). Methods: 8 weeks-old SHR and Wistar Kyoto (WKY normotensive rats) were infused (14 days, subcutaneous osmotic pumps) with ANP (100 ng/hr/rat) or saline (S). After experimental period, we determined in kidney: thiobarbituric acid-reactive substances (TBARS, nmol/mg protein), glutathione concentration (mg/mg protein), and activity of: glutathione peroxidase (GPx, pmol/min.mg protein), catalase (CAT, pmol/mg protein) and superoxide dismutase (SOD, USOD/mg protein). Results: TBARS Glutathione GPx CAT SOD WKY S 0,113±0,015 0,271±0,038 1,449±0,230 0,847±0,102 7,691±0,505 WKY ANP 0,098±0,010 0,398±0,028* 1,890±0,302 0,956±0,098 8,021±1,654 SHR S 0,162±0,025* 0,178±0,046* 3,315±0,225* 0,951±0,105 7,098±0,653 SHR ANP 0,082±0,009# 0,374±0,027# 3,920±0,845 1,101±0,142 8,452±0,779 *p< 0,01 vs WKY S; #p<0,01 vs SHR S. SHR shown higher levels of TBARS and GPx activity than WKY rats. Renal glutathione concentration was lower in hypertensive rats than in normotensive ones. CAT and SOD basal activities were similar in both groups. In WKY rats, ANP treatment increased glutathione concentration. In hypertensive rats, ANP chronic infusion diminished TBARS and increased glutathione renal concentration, indicating a reduction in renal oxidative stress. Conclusion: Chronic treatment with ANP improved, almost in part, renal oxidative damage in this model of hypertension in rat.