Effect of Salt on Isoprostanes in Salt-Sensitive Essential Hypertension
- 1 March 2006
- journal article
- Published by Wolters Kluwer Health in Hypertension
- Vol. 47 (3), 434-440
- https://doi.org/10.1161/01.hyp.0000202480.06735.82
Abstract
The controversy over beneficial versus harmful effects of salt on cardiovascular outcomes may be caused by different effects of salt on intermediate phenotypes of hypertension not characterized in epidemiological studies. Hence, we investigated acute effects of salt on oxidative stress in hypertensive subjects classified as salt sensitive (SS, n=14) or salt resistant (SR, n=13) by an inpatient protocol of salt loading (460 mmol NaCl) and salt depletion (10 mmol NaCl and furosemide). Oxidative stress was assessed by measuring the plasma isoprostane 8-iso-PGF2α. SS had lower plasma renin activity, higher aldosterone/renin ratios, and exaggerated endothelin and catecholamine responses to salt depletion compared with SR. Baseline lipid-bound isoprostanes (749±70 pmol/L) were 83% of the total and were slightly but not significantly higher in SS than SR. Baseline free isoprostanes did not differ between groups. After salt loading, lipid-bound isoprostanes were higher in SS (945±106) than SR (579±57; P P value not significant). Free isoprostanes were decreased by salt depletion only if data in all of the patients were analyzed together. Total isoprostanes followed the pattern of the lipid-bound fraction. Correlations between salt depletion-induced changes in lipid-bound isoprostanes, plasma renin activity ( r =0.45; P r =−0.41; P <0.04) suggested that the more SS the patient, the greater the reduction of oxidative stress by salt depletion. Our research is the first to show that salt affects oxidative stress acutely in humans, particularly in SS hypertension, which may explain the controversial results of epidemiological studies on salt and morbidity and may have implications for therapy.Keywords
This publication has 40 references indexed in Scilit:
- Effect of Dietary Sodium Intake on Blood LipidsHypertension, 2004
- Salt Intake, Oxidative Stress, and Renal Expression of NADPH Oxidase and Superoxide DismutaseJournal of the American Society of Nephrology, 2003
- Oxidative stress in malignant and non-malignant phase hypertensionJournal of Human Hypertension, 2002
- Harmful effects of dietary salt in addition to hypertensionJournal of Human Hypertension, 2002
- Is aldosterone the missing link in refractory hypertension?: aldosterone-to-renin ratio as a marker of inappropriate aldosterone activityJournal of Human Hypertension, 2002
- Functional Characterization of the Ocular Prostaglandin F2α (PGF2α) ReceptorPublished by Elsevier ,1997
- Effect of a nonselective endothelin antagonist on vascular remodeling in deoxycorticosterone acetate-salt hypertensive rats. Evidence for a role of endothelin in vascular hypertrophy.Hypertension, 1994
- Findings of the International Cooperative INTERSALT Study.Hypertension, 1991
- Abnormal relationship between sodium intake and sympathetic nervous system activity in salt-sensitive patients with essential hypertensionKidney International, 1982
- Abnormally sustained aldosterone secretion during salt loading in patients with various forms of benign hypertension; relation to plasma renin activityJCI Insight, 1970