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The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it. [ABSTRACT FROM AUTHOR]

Untreated hypertensive patients show increased oxidative stress and decreased antioxidant enzyme activity in mononuclear cells. Therefore, the objective of this study was to determine whether or not the low antioxidant enzyme activity observed in mononuclear cells of hypertensive subjects is in part dependent on a defective activity of antioxidant mechanisms. Activity and mRNA level of antioxidant enzymes, CuZn- and Mn-superoxide dismutases, catalase, glutathione peroxidase type 1, and glutathione reductase were simultaneously measured in mononuclear cells of controls (n = 38) and hypertensive subjects (n = 35), in the absence of and during antihypertensive treatment. An increase in oxidative stress and a decrease in the activity of cytoplasmic enzymes were observed in untreated hypertensive patients. Concurrently, CuZn-superoxide dismutase and glutathione reductase mRNA levels were significantly reduced, and glutathione peroxidase type 1 mRNA was slightly reduced. In contrast, increased activity and mRNA levels of the mitochondrial Mn-superoxide dismutase were observed. Antihypertensive treatment, nonpharmacologic with or without a drug regimen of β-blocker or angiotensin AT1 receptor blocker was administered for a 3-month period. Afterward, after the improvement in oxidative stress during treatment, a recovery of the cytoplasmic antioxidant enzymatic activity and a more profound decrease in mRNA levels were observed for CuZn-superoxide dismutase, glutathione peroxidase type 1, and glutathione reductase. Meanwhile mitochondrial enzymatic activity decreased, as did the mRNA level. The inadequate response of the main cytoplasmatic antioxidant systems, as well as of the enzymes participating in the maintenance of glutathione levels, may contribute to the vulnerability of hypertensives to oxidative stress. [Copyright &y& Elsevier]

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it. [ABSTRACT FROM AUTHOR]

Objectives Familial hypercholesterolemia (FH) is characterized by increased oxidative stress (OS) levels. In the postprandial state, lipids and lipoproteins modulate OS status through their impact on pro-oxidant and antioxidant mechanisms. The objective of this study was to evaluate in patients with FH the response to an unsaturated oral fat load test (OFLT) by analyzing the mRNA levels of genes involved in the glutathione and thioredoxin antioxidant systems. Design and Methods We analyzed 14 FH patients and 20 normolipidemic and normoglycemic controls. In both groups, mRNA values of antioxidant enzyme genes (glutathione and thioredoxin systems) were determined at baseline and at 2, 4, 6, and 8 h after OFLT by real time PCR. Results In the fasting state the mRNA levels of antioxidant enzymes GPX4 and the GSR, GSS, and GCLC enzymes (involved in glutathione regeneration and synthesis) and thioredoxin (TXN), were significantly increased in the FH group compared to the healthy controls. Some genes (GPX1 and GPX4) were increased at 4 h in both groups, but values for the rest of the antioxidant enzyme mRNAs were decreased in FH patients after 4 h from unsaturated OFLT and were increased in controls. Conclusions We concluded that an OFLT with predominantly unsaturated fat has a different effect on postprandial antioxidant enzyme mRNA levels in controls than in FH patients. Increased antioxidant enzyme mRNA is not the main way to reduce postprandial oxidative stress in FH. This difference could determine the influence of dietary patterns in these patients. [ABSTRACT FROM AUTHOR]