Milena Vuletic

Oxidative stress in fetal distress: potential prospects for diagnosis.

Our aim was to investigate the relation between fetal distress and oxidative stress. Fetal distress was associated with increased concentration of superoxide in the fetal blood and with significant increase of the level of H2O2 in both maternal and fetal blood. The activity of superoxide dismutase was increased roughly sixfold (p<0.01) in the maternal (7330 +/- 2240 U/g of hemoglobin in controls (C) and 36811 +/- 16862 U/g in fetal distress (FD)) and fetal blood (C: 5930 +/- 2641 U/g; FD: 41912 +/- 17133 U/g). In contrast, fetal distress was related to a considerable decrease of catalase activity in both maternal (C: 26011 +/- 8811 U/g; FD: 7212 +/- 1270 U/g) and fetal blood (C: 37194 +/- 9191 U/g; FD: 6173 +/- 1965 U/g). From this we concluded that in fetal distress, the maternal and fetal bloods are exposed to superoxide- and H2O2-mediated oxidative stress, which could be initiated by hypoxic conditions in the fetal blood and placenta. A tremendous increase/decrease of the activities of superoxide dismutase/catalase in the blood of women bearing a distressed fetus in comparison to healthy subjects implies that the assessment of superoxide dismutase/catalase activity could be of use for establishing a timely and accurate ante- or intrapartum diagnosis of fetal distress.

Assessment of Oxidative Status in Patients with Acute Kidney Injury: A Pilot Study

Extensive experimental evidence confirms the role of oxidative stress as a major contributor to the pathogenesis of acute kidney injury (AKI). However, less information is available on the evolution of prooxidant-antioxidant parameters from early to end-phase renal function decline in humans. This study aimed to determine the oxidative status in dynamic throughout the evolutionary phases of the disease. The study included patients with cardiovascular pathology and AKI hospitalized in the intensive care unit (n = 69) and age-matched healthy controls (n = 30). They were followed through three phases of AKI; the first [corrected] phase was the phase of diagnosis, which is characterized by oliguria/anuria, the [corrected] second phase was established diuresis, and the [corrected] third phase was the polyuric phase. In these phases of the disease, blood samples were taken from the patients for biochemical analysis. From the collected whole blood, we measured spectrophotometrically prooxidants: index of lipid peroxidation, measured as Thiobarbituric acid reactive substances (TBARS), nitrite (NO₂⁻), superoxide anion radical (O₂⁻) and hydrogen peroxide (H₂O₂), and antioxidants: activity of superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) from erythrocyte lysate. Comparing the results of the three measurements, a significant difference was found in the levels of NO₂⁻ and GSH, both of which increased in the second phase (P < 0.05) and then decreased in the third phase, and a significant increase in TBARS, which was elevated in the second phase (P < 0.05) and did not change significantly until the third phase. Our results showed phase-dependent modification in 3 parameters of the oxidative status (TBARS, NO₂⁻ and GSH). Whether these changes contribute to the deterioration of renal function in AKI remains to be established.

Alteration in basal redox state of young male soccer players after a six-month training programme.

Despite worldwide popularity of soccer, there are still insufficient data about the effects of training process on oxidative stress-induced damage, which may occur during chronic exercise. The present study aimed to determine the effects of a six-month training programme on basal redox status of young male soccer players. The study included 26 male soccer players, aged 12-13, who participated in a six-month training programme, and 26 age-matched non-athletes who were not implemented in the training process. Blood samples were collected (before and after six-month training programme) in order to measure the following oxidative stress markers: index of lipid peroxidation (measured as TBARS), nitrites (NO2-), superoxide anion radical (O2-), hydrogen peroxide (H2O2), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) level. After six months, the levels of TBARS and NO2- were significantly increased, while the O2- and H2O2 remained unchanged. On the other hand, SOD and CAT activity increased, while GSH decreased. A carefully prepared training programme could strengthen most components of antioxidant defence systems and, except lipid peroxidation, does not promote oxidative stress in response to regular physical activity. These findings could help in the improvement of training programmes for young athletes.

The Effects Of Two Fitness Programs With Different Metabolic Demands On Oxidative Stress In The Blood Of Young Females

Abstract The aim of the present study was to assess the effects of two metabolically different exercise programs on the redox state of women who were physically inactive before the beginning of the study. For this purpose, participants (women 25±5 years old) chose one of two popular fitness programs, Pilates or Tae Bo, and attended it 3 times a week for 12 weeks. At the beginning and end of the study, body composition analysis and venous blood sampling were performed. The levels of superoxide anion radical, hydrogen peroxide, nitric oxide and lipid peroxidation were measured in plasma, and the levels of reduced glutathione and the activity of superoxide dismutase and catalase were measured in erythrocytes. Only the Tae Bo program induced changes (positive) in body composition, whereas both exercise programs induced slight oxidative stress in exercisers. In the Tae Bo group, the levels of hydrogen peroxide were significantly increased, whereas the levels of reduced glutathione were decreased after three months of training. In the Pilates group, hydrogen peroxide and catalase activity were increased, and nitrites decreased. However, at the end of the study, those two groups had no significantly different values for any pro/antioxidant compared with the subjects who served as controls. This finding suggests that moderate physical activity, such as recreational fitness programs, may induce the increased production of reactive oxygen species but do not lead to a serious disturbance of the redox homeostasis of exercisers.