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

SAVIGNANO L; MOLINARI A; BOUCHET GONZALO; CANIFFI CAROLINA; ROMERO MARIANA; TOMAT ANALÍA; ELESGARAY ROSANA; ARRANZ CRISTINA; COSTA MARÍA ÁNGELES

Workshop; Internacional Workshop: 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.