Figure 4.

Summary of the effect of the 7-day high-salt (HS) diet on parameters of oxidative stress measured in the present study in young healthy individuals. This figure summarizes the most commonly known effects of the superoxide radical (O₂•), nitric oxide radical (NO•), hydroxyl radical (OH•), and peroxyl radical (ROO•) in the formation of oxidative stress (blue), nitrosative stress (green), and lipid peroxidation (orange). The effects of enzymatic (green) and non-enzymatic (blue) components of antioxidative defense are also described, as well as the spectrum of their antioxidative activity (full arrow—the reaction they catalyze, dashed line—the spectrum of antioxidative activity). Radicals, metabolites, and enzymes that were measured in the present study as markers of oxidative stress and antioxidative defense are indicated in red filled circles. Seven days of the HS diet increased oxidative stress levels, which manifested as increased lipid peroxidation (increased serum TBARS and 8-iso-PGF2ɑ) and increased intracellular H₂O₂ and ONOO- production in peripheral blood leukocytes (increased DCF-DA in granulocytes and monocytes), and decreased antioxidant defense which manifested as decreased antioxidant capacity of plasma (FRAP) and serum catalase protein concentrations in young healthy individuals. ONOO—peroxynitrite; NO•—nitric oxide radical; O₂•—superoxide; H₂O₂—hydrogen peroxide; HO•—hydroxyl radical; ROO•—peroxyl radical; DHE —dihydroethidium; DCF-DA—2’7’-dichlorodyhydrofluorescein diacetate; TBARS—thiobarbituric acid reactive substances; FRAP—ferric-reducing ability of plasma; SOD—superoxide dismutase; CAT—catalase; GPx—glutathione peroxidase.