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Biomedical subjects

Y Alicigüzel

Publications and source records attributed to Y Alicigüzel.

11 recordsLinked to original sources
PubMed2002

The effect of exercise on brain antioxidant status of diabetic rats.

BACKGROUND: To investigate the effect of exercise on brain antioxidant status of diabetic rats. METHODS: Wistar rats were divided into four groups: Control (C), exercise (CE), diabetic (D), and diabetic+exercise (DE). Diabetes was induced by single administration of streptozotocin (60 mg/kg). We used an aerobic exercise program for 8 weeks of CE and DE rats. After the end of the experimental period, Cu, Zn-superoxide dismutase (Cu, Zn-SOD), catalase (CAT), glutathione peroxidase (GSH-Px), xanthine dehydrogenase (XDH) and xanthine oxidase (XO) activities and thiobarbituric acid reactive substances (TBARS) levels of brain were measured. RESULTS: Diabetes caused significant reduction of brain Cu, Zn-SOD and GSH-Px activities in the D and DE groups. CAT activity was decreased only in the D group. Exercise did not alter CAT activity of brain, whereas markedly increased Cu, Zn-SOD activity in the DE group. In contrast to diabetes-related decrease in the activity of Cu, Zn-SOD, increase in the XO and GSH-Px activities were observed in the DE group compared with the D group. XDH activity was significantly reduced in two exercise groups according to the control rats, but the decrease was not accompanied with the activity of XO elevation in all groups. Increase in the XO activity and decrease in the XDH activity in the DE rats have revealed that diabetes and exercise have potentially effect in free radical production. On the other hand, TBARS levels were found to be elevated in all diabetic animals. CONCLUSIONS: Our results show that aerobic exercise did not affect lipid peroxidation of brain, but in diabetic condition improved antioxidant defence.

Animals↗
PubMed2001

Erythrocyte, plasma, and serum antioxidant activities in untreated toxic multinodular goiter patients.

Erythrocyte, plasma, and serum antioxidant activities were studied in patients with newly diagnosed and untreated toxic multinodular hyperthyroid goiter and compared to healthy control subjects. Erythrocyte antioxidant enzyme activities, glutathione, malondialdehyde, and ceruloplasmin levels were significantly increased, whereas serum vitamin E, plasma vitamin C, and selenium levels were decreased in hyperthyroid patients compared to control subjects. The findings show that untreated toxic multinodular goiter causes profound alterations in components of the antioxidant system in erythrocytes indicative of increased oxidative stress. Taken together, these data suggest that hyperthyroid patients may benefit from dietary supplements of antioxidants.

Adult↗
PubMed2001

Effect of the herbicide 4-CPA on human erythrocyte antioxidant enzymes in vitro.

To investigate the possible role of oxygen free radicals and oxidant stress in the toxic effects of phenoxyherbicides, we studied the in vitro effect of 4-chlorophenoxyacetic acid (4-CPA) on various human erythrocyte antioxidant enzymes, namely glucose-6-phosphate dehydrogenase, catalase, selenium-dependent glutathione peroxidase, glutathione reductase and Cu/Zn-superoxide dismutase. 4-CPA added in a dose of 1 ppm to human erythrocytes for 1 h caused a significant reduction in glucose-6-phosphate dehydrogenase (P <0.001) and catalase (P <0.001) activities, but did not significantly affect the activities of other enzymes. Such selective inactivation of specific erythrocyte antioxidant enzymes may play a role in the toxic effects of phenoxyherbicides.

2,4-Dichlorophenoxyacetic Acid↗
PubMed2000

Effects of propylthiouracil treatment on antioxidant activities in blood of toxic multinodular goiter patients.

Erythrocyte, serum and plasma antioxidant activities and the effects of propylthiouracil (PTU) treatment on these activities were studied in patients with toxic multinodular goiter. The activities of the erythrocyte antioxidant enzymes (glucose-6-phosphate dehydrogenase, catalase, Cu/Zn-superoxide dismutase, selenium (Se)-dependent glutathione peroxidase and glutathione reductase) and the levels of erythrocyte Se, serum ceruloplasmin and plasma malondialdehyde were significantly higher while serum vitamin E, plasma vitamin C and plasma Se were lower in hyperthyroid patients. PTU treatment, not for 1 but for 3 months caused a partial reversal of antioxidant activities to euthyroid levels. It is suggested that alterations in blood antioxidant activities following PTU treatment might be due to the antioxidant and/or antithyroid effect of this drug.

Adult↗
PubMed1998

Effects of sulfur dioxide inhalation on antioxidant enzyme activities in rat erythrocytes.

Swiss-Albino male rats were exposed to sulfur dioxide (SO2) (10 ppm) one hour daily for 60 days and the effect on the erythrocyte antioxidant enzyme activities was studied. Erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD), superoxide dismutase (Cu,Zn-SOD), glutathione peroxidase (GSH-Px), catalase (CAT), glutathione-S-transferase (GST) activities and thiobarbituric acid reactive substances (TBARS) of 30 rats (14 controls and 16 sulfur dioxide groups) were measured. There were no significant differences in the catalase and G-6-PD activities of SO2 group as compared with controls. GSH-Px and GST activities in SO2 group were significantly higher than those in the control group. But, there was a significant decrease in the SOD activity. The rate of TBARS formation was enhanced significantly in erythrocytes of the SO2 group relative to the control group. These results reveal that SO2 inhalation enhanced lipid peroxidation in the erythrocyte and influence the antioxidant enzymes of erythrocyte.

Analysis of Variance↗
PubMed1997

Effect of cadmium on antioxidant status in alloxane-induced diabetic rats.

Fifty-two healthy Swiss Male Albino rats aged two mo were used in this study. They were divided into four groups: control (C), diabetic (D), cadmium (Cd), and diabetic + Cd (D + Cd) groups. Diabetic condition was induced in D and D + Cd groups by administration of alloxane (5 mg/100 g). After this treatment, Cd and D + Cd groups were injected with CdCl2 i.p. (2 mg/kg/wk). At the end of the 2-mo experimental period, thiobarbituric acid reactive substances (TBARS), plasma and erythrocyte selenium (Se), plasma ceruloplasmin (Cp), and vitamin E (vit E) were determined in four groups of rats. The erythrocyte Se was lower in the experimental groups than in the controls. Plasma Se was significantly decreased in the D and D + Cd groups compared with the control group. Plasma Cp was unaltered. Plasma vit E was significantly decreased in Cd group in comparison with the C, D, and D+Cd groups.

Alloxan↗
PubMed1997

Increased resistance to oxidative stress in normal and glucose-6-phosphate dehydrogenase-deficient hemolysates in the presence of enzyme substrates.

Erythrocytes and hemolysates from 10 normal and 10 glucose-6-phosphate dehydrogenase-deficient individuals were incubated with cumene hydroperoxide, and free radical-induced lipid peroxidation was monitored by chemiluminescence. Chemiluminescence intensities in erythrocytes of normal and deficient subjects were similar in the presence or absence of glucose-6-phosphate dehydrogenase substrates. Hemolysates of normal and deficient subjects also showed similar chemiluminescence in the absence of substrates. However, with the addition of substrates to the incubation medium, deficient hemolysates reached maximum chemiluminescence intensity within a shorter period, and maximum values were higher than in normal hemolysates. We believe this offers a new means of detection of glucose-6-phosphate dehydrogenase-deficient patients.

Benzene Derivatives↗
PubMed1997

Erythrocyte selenium-glutathione peroxidase activity is lower in patients with coronary atherosclerosis.

To obtain further insight into the role of erythrocyte antioxidant systems in the development of atherosclerosis, intraerythrocyte enzyme activities and selenium levels in erythrocytes were determined in 37 patients with angiographically proved coronary artery stenosis and 15 subjects with normal coronary angiograms as controls. In a preliminary study, the enzymatic activities of glucose-6-phosphate dehydrogenase (G6PD), glutathione reductase (GR) and selenium-dependent glutathione peroxidase (Se-GPx) were measured in both venous and arterial blood samples obtained from patients before angiography. The data of the preliminary study, which showed that only the Se-GPx decreased in the patients, led us to concentrate on the Se-GPx and Se levels to determine the changes in these variables. Our results showed that there was a decrease in both the activity of Se-GPx and Se levels in erythrocytes parallel to the increase in the severity of coronary artery disease. It was concluded that these parameters might be used as determinants in the assessment of the severity of the disease.

Adult↗
PubMed1996

Continuous monitoring of hydroperoxide-induced peroxidation in human erythrocytes by low-level chemiluminescence.

We studied the effect of cumene hydroperoxide, t-butyl hydroperoxide, and hydrogen peroxide on intact healthy human erythrocytes (15 g hemoglobin/dl) using chemiluminescence to monitor peroxidation. We measured the chemiluminescence spectrum, the process of hemolysis, the pH shift, and absorbance spectrum during the incubation with chemicals producing oxidative stress. Maximum chemiluminescence was reached with cumene hydroperoxide at about 50 min, but with t-butyl hydroperoxide at 100 min. The effect of organic hydroperoxide was concentration dependent, whereas the effect of hydrogen peroxide was independent of concentration. Peroxides induced hemolysis after 30 min. The pH shift to alkaline was observed in the first 20-min period. Incubation with organic hydroperoxides induced a decrease in absorption at 580, 545, and 345 nm. Hydrogen peroxide induced a decrease in the same period of time but this returned to the normal range by 120 min. There was no change in absorption at 420 nm with any of the peroxidative agents. Our results suggest that low-level chemiluminescence is a useful model for studying hydroperoxide-induced peroxidation in human erythrocytes.

Antioxidants↗
PubMed1990

Erythrocyte glucose-6-phosphate dehydrogenase (1.1.1.49) deficiency in Antalya province, Turkey: an epidemiologic and biochemical study.

Glucose-6-phosphate dehydrogenase (1.1.1.49) activity was assessed in 1986-1988 in blood samples from 1,521 individuals from 375 families living an Antalya city and adjacent villages by Beutler's fluorescence spot test. The families were randomly selected by the State Statistical Institute. Complete deficiency occurred in 7.4% of males and 1.8% of females. Mean enzyme activity was 6.77 +/- 1.07 IU/g Hb in normals and ranged between 0 and 0.48 IU/g Hb in those considered deficient. Kinetic measurements made with partially purified enzyme showed that GdB+ and GdB- variants were present in normal and in deficient subjects, respectively.

Adolescent↗