Role of superoxide and hydrogen peroxide in hypertension induced by an antagonist of adenosine receptors

Lipid Peroxidation and Antioxidants in Arterial Hypertension

“…Several prohypertensive effects have been described for H2O2, such as increased vasoconstriction, vascular hypertrophy and hyperplasia, decreased diuresis and natriuresis and also increased spinal sympathetic outflow [7,50,[52][53][54][55][56][57][58]. Increasing evidence has also shown that H2O2 amplifies oxidative stress by stimulating ROS generation by NADPH oxidases, XO and eNOS [7,51].…”

“…Hypertensive patients have reduced activity and decreased content of antioxidant enzymes, including SOD, GPx, and catalase [43]. However, several studies have also described an adaptive increase in antioxidant enzyme activities in some experimental models of hypertension [50,111,112]. The uncoordinated activity of antioxidant enzymes may aggravate oxidative stress.…”

“…The hypothesis that oxidative stress contributes to arterial hypertension is supported by several lines of evidence: (1) the induction of oxidative stress by the administration of lead or the glutathione synthesis inhibitor, buthionine sulfoximine, or the SOD inhibitor, sodium diethyldithiocarbamate, increases blood pressure in rats [48,84]; (2) the infusion of H2O2 into the renal medulla leads to hypertension [48]; the treatment of hypertensive animals with antioxidants or inhibitors of ROS production prevents or attenuates hypertension [50,[85][86][87]; (3) the manipulation of genes related to ROS generation or elimination can alter blood pressure [88,89]; (4) the in vitro exposure of cells and tissues to exogenous oxidants reproduces events involved in the pathophysiology of hypertension [43]; (5) systemic and tissue redox dysfunction appears to precede the blood pressure elevation [90].…”

“…NO in the rostral ventrolateral medulla [47]. In recent years H2O2 has also emerged as a pivotal molecule in the pathophysiology of arterial hypertension [48][49][50]. Of note, H2O2 seems to be even more harmful than O2 .-due to its higher life span and diffusibility within and between cells [7,51].…”

“…The combined antioxidant activities of aqueous-and lipid-antioxidants, including GSH, vitamins, uric acid, bilirrubin, albumin, etc, can be evaluated in the plasma and serum by several assays that measure the ability of the antioxidants present in the sample to inhibit the oxidation of the cation radical ABTS + [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid] (Total Antioxidant Status assay), to reduce a ferric-tripyridyltriazine complex (Ferric Reducing Ability of Plasma, FRAP assay) or to trap free radicals (Oxygen Radical Absorbance Capacity, ORAC assay; Total radical Trapping Parameter, TRAP) [50,[136][137][138].…”