Comparison of oxidative stress indicators in plasma of recent-onset and long-term type 1 diabetic patients

Oxidative stress was compared in plasma of 15 recently diagnosed (5 yr) type 1 diabetic patients with 15 healthy volunteers. Lipid peroxidation indices measured in plasma included thiobarbituric acid-reactive substances (TBARS), conjugated dienes, and lipid hydroperoxide (ROOH). The values obtained were corrected for phospholipid to minimize this as a confounding factor. In recently diagnosed diabetics, plasma conjugated lipid dienes were significantly elevated. However, in long-standing diabetics there was a marked increase in TEARS, conjugated dienes, and lipid hydroperoxide levels. Our findings showed increased oxidative stress in type 7 diabetics regardless of metabolic control and that conjugated diene measurement appeared to be the most sensitive bioindicator of oxidant stress in our population

Influence of propylthiouracil treatment on oxidative stress and nitric oxide in Basedow disease patients

Oxidative stress parameters and nitric oxide (NO) values were determined in 27 newly diagnosed Basedow patients before and afer 1 mo of propylthiouracil (PTU) therapy and in 15 healthy controls. Basedow patients exhibited increased triiodothyronine (T-3) and thyroxine (T-4) and decreased thyroid-stimulating hormone (TSH) values compared to controls. Significantly higher thiobarbituric acid-reactive substances (TBARS), NO and glutathione (GSH) levels, and CuZn superoxide dismutase (CuZn SOD) activity were found in Basedow patients in comparison to controls, regardless of sex. Treatment with PTU (3 x 100 mg/d for 30 d) was effective in decreasing T-3 and T-4 and increasing TSH levels. Significantly decreased NO and TBARS and increased GSH and CuZn SOD levels were observed in PTU-treated Basedow patients compared to pre-PTU administration. PTU-treated patients compared to controls still exhibited significantly higher T-3 and lower TSH values and higher NO, TBARS, GSH, and CuZn SOD levels. The induced antioxidant defense and decrease in NO values in response to PTU therapy emphasizes the role of PTU as an antithyroid drug, where the ability to diminish hyperthyroidism results in decreased catabolism and lower oxidant generation

Biochemical evaluation of oxidative stress in propylthiouracil treated hyperthyroid patients. Effects of vitamin c supplementation

In this study the impact of vitamin C supplementation on oxidative damage as assessed by thiobarbituric acid reactive substances and markers of antioxidant status: namely Cu/Zn superoxide dismutase, glutathione peroxidase, glutathione reductase and glutathione were investigated in 24 hyper-thyroid patients under propylthiouracil therapy (3x100 mg/day) for five days and in 15 healthy controls. Ascorbic acid (1000 mg/day) was given as a supplement for 1 month to both the patients and controls during the study period. Heparinised blood samples were taken at the beginning and the end of one month ascorbic acid supplementation

Lipid peroxidation and antioxidant status in experimental animals: Effects of aging and hypercholesterolemic diet

Effects of aging and hypercholesterolemic diet on lipid peroxidation and antioxidant status were investigated in rats. The rats were divided into four groups of ten: Group I; young rats receiving standard lab chow; Group II; young rats on hypercholesterolemic diet (0.4 g/rat/day); Group III; aged rats receiving standard lab chow; Group IV; aged rats on hypercholesterolemic diet (0.4 g/rat/day). Plasma lipid peroxidation end product level was determined as thiobarbutiric acid reactive substances (TEARS). Plasma cholesterol concentration was analyzed by a kinetic enzymatic method. Erythyocyte superoxide dismutase (CuZn SOD), glutathione peroxidase (GSH Pr) and glutathione (GSH) levels were determined spectrophotometrically. Cholesterol values were found to be significantly high (p p > 0.02) and GSH (p p > 0.02) was observed in aged rats. In young rats hyperchlesterolemic diet caused a significant increase in both GSH and CuZnSOD levels. Our results indicate an imbalance between radical production and destruction in favour of prooxidant conditions in the young rats and the induction by hypercholesterolemic diet of the antioxidative response in erythrocytes. (C) 1997 Elsevier Science B.V

The effect of iron supplementation on GSH levels, GSH-Px, and SOD activities of erythrocytes in L-thyroxine administration

Our aim was to study the effect of iron supplementation on the following aspects of erythrocyte metabolism in experimental hyperthyroidism: glutathione (GSH) levels, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) activities. Hyperthyroidism induced by L-thyroxine administrations significantly raised erythrocyte GSH, GSH-Px and SOD levels of the rats (P < 0.001). Likewise, we observed that iron supplementation induced significant rises in erythrocyte GSH, GSH-Px and SOD levels (P < 0.001) as compared with the control group. The erythrocyte GSH, GSH-Px and SOD levels of hyperthyroidism-induced iron-supplemented animals were significantly higher when compared with either the iron-supplemented group (P < 0.001) or the only L-thyroxine-administered hyperthyroid group (P < 0.001, P < 0.05, P < 0.01, respectively). The results of this study show that L-thyroxine administration and/or iron supplementation increases GSH, GSH-Px and SOD levels of erythrocytes

Evaluation of oxidative stress parameters in blood of patients with laryngeal carcinoma

Objectives: In this study, plasma lipid peroxidation as assessed by thiobarbituric acid reactive substances and erythrocyte antioxidant status markers namely CuZn superoxide dismutase, glutathione peroxidase, glutathione and plasma levels of vitamin C and E were investigated in 20 patients with larygneal carcinoma and 15 healthy controls

Oxidative stress in heart tissue of hyperthyroid and iron supplemented rats

This study was designed to investigate the effect of hyperthyroidism and/or iron supplementation on cardiac oxidative stress parameters-the lipid peroxidation end product glutathione (GSH), glutathione peroxidase (GSH-Px), and superoxide dismutase (CuZnSOD) - in rats, In plasma, ferritin as an indicator of iron status and glutamate oxaloacetate transaminase (GOT) as an indicator of damage to the heart tissue were analyzed. Our findings show that hyperthyroidism increased lipooxidative damage as reflected by higher lipid peroxidation end product levels and elevated antioxidant defense parameters-GSH and GSH-Px. Iron supplementation per se does not affect oxidative stress parameters studied in the euthyroid state. Although iron increased lipid peroxidation in the hyperthyroid state, this effect was less than that seen in euthyroidism. Iron supplementation to hyperthyroid rats significantly lowered plasma ferritin levels, suggesting increased iron elimination with consequently reduced oxidative stress

Laryngeal cancer: in relation to oxidative stress

This study was designed to investigate the oxidative stress parameters in laryngeal cancer and cancer-free adjacent tissues. Lipid peroxidation end product and the endogenous antioxidant components-CuZn superoxide dismutase (CuZnSOD) glutathione peroxidase (GSH Px), glutathione reductase (GSSG Rd) and glutathione (GSH)-were analysed by spectrophotometric and kinetic methods. Laryngeal cancer tissue exhibited higher lipid peroxidation than cancer free adjacent tissue. CuZn SOD and GSH Px activities and GSH level were significantly higher and GSSG Rd activity significantly lower in the cancer tissue. Detection of the antioxidant status may be useful to determine the tumour resistance to therapy, to choose the correct radiotherapy/chemotherapy and to monitor the effectiveness of the therapetic strategy