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Öğe Effect of pentoxifylline on antioxidant status of healthy and endotoxemic New Zealand white rabbits(VETERINARNI A FARMACEUTICKA UNIVERZITA BRNO, 2005) Keskin, E; Oztekin, E; Col, R; Sivrikaya, A; Uney, K; Yazar, EIn this study, effect of pentoxifylline on antioxidant status of healthy and endotoxemic rabbits was investigated. Endotoxemia was induced with E. coli lipopolysaccharide in New Zealand white rabbits. Forty rabbits were randomly divided into four equal groups. Group 1 served as control. Animals in Group 2 were given lipopolysaccharide (400 mu g/kg) intravenously, in Group 3 pentoxifylline (50 mg/kg) was injected intraperitoneally. In Group 4; pentoxifylline (50 mg/kg intraperitoneally) and lipopolysaccharide (400 mu g/kg, intravenously) were injected simultaneously. Animals were killed, and liver, heart and kidney samples were taken at 6 hours after administrations. Malondialdehyde, superoxide dismutase, glutathione peroxidase and reduced glutathione levels of heart, liver and kidney tissues were measured. Lipopolysaccharide caused significant increases (p < 0.05) in hepatic malondialdehyde, and cardiac, hepatic and renal glutathione peroxidase activities. It however, caused significant (P < 0.05) decrease in hepatic superoxide dismutase activity when compared to control group. Pentoxifylline caused significant (p < 0.05) increases of cardiac and hepatic malondialdehyde levels, cardiac superoxide dismutase and renal glutathione peroxidase activities, and cardiac, hepatic and renal reduced glutathione levels when compared to control group. As a result, pentoxifylline has no exactly beneficial effect on the antioxidant status of healthy and endotoxaemic New Zealand white rabbits at the administered dose and route. Although it was stated that pentoxifylline may be beneficial in endotoxaemia, its antioxidant effect may be dependent on dose, administration route and animal species. For this reason, when pentoxifylline is used in endotoxaemia, a treatment protocol should be done for each animal species.Öğe Effect of zinc deficiency and supplementation on lipid peroxidation of renal tissue in ovariectomized rats(HUMANA PRESS INC, 2004) Baltaci, AK; Sunar, F; Mogulkoc, R; Oztekin, EThe aim of this study was to investigate how zinc deficiency and supplementation affects lipid peroxidation in the renal tissue in ovariectomized rats. Four study groups were formed with 10 Spraque-Dawley rats each. Two of the groups served as normal and ovariectomized controls; the other two were ovariectomized rats that were zinc deficient and zinc supplemented, respectively. The zinc-deficient ovariectomized rats showed greater renal and plasma lipid peroxidation, as indicated by higher malondialdehyde levels than all other groups (p<0.05). These values were higher in the ovariectomized controls than those of the normal controls and of the ovariectomized, zinc-supplemented groups (p<0.05), which, in, turn, showed no significant differences of their respective renal and plasma malondialdehyde values. The renal and erythrocyte glutathione levels in the zinc-supplemented rats were higher than those in all other groups (p<0.05). The zinc-deficient group had the lowest renal and erythrocyte glutathione levels (p<0.05). The renal tissue zinc levels in the ovariectomized rats were higher than those in the zinc-deficient animals, but lower than in the normal controls and zinc-supplemented rats (p<0.05). The zinc-supplemented animals had the highest renal tissue zinc levels (p<0.05). The results of this study suggest that zinc deficiency increases renal tissue damage in ovariectomized rats and that zinc supplementation can be used to prevent this condition.Öğe Effects of different doses of tilmicosin on malondialdehyde and glutathione concentrations in mice(VETERINARNI A FARMACEUTICKA UNIVERZITA BRNO, 2004) Yazar, E; Oztekin, E; Sivrikaya, A; Col, R; Elmas, M; Bas, ALThe aim of this study was to follow the effects of different doses of tilmicosin on malondialdehyde and reduced glutathione levels of heart and liver, and on selected haematological indices. Forty male Balb/C mice were used throughout the experiment. They were divided into four groups (n = 10), and injected subcutaneously as follows: Group I (control), with isotonic saline solution, Group 2 with 25 mg/kg body weight of tilmicosin, Group 3 with 50 mg/kg, and Group 4 with 75 mg/kg of tilmicosin in single injections. After three days, plasma, cardiac and hepatic malondialdehyde and reduced glutathione levels were measured with spectrophotometer. Red blood cell, white blood cell, platelet, haemoglobin, packed cell volume and percentage of leukocytes were also determined. At the end of the experiment, tilmicosin did not cause any statistically significant (P > 0.05) changes in haematological parameters such as red blood cells, white blood cells, platelet, haemoglobin, packed cell volume and percentage of leukocytes. Hepatic malondialdehyde and reduced glutathione levels increased (P < 0.05) only at the highest dose of tilmicosin. The results indicate that tilmicosin did not cause lipid peroxidation in the heart.Öğe The effects of zinc deficiency and supplementation on lipid peroxidation in bone tissue of ovariectomized rats(ELSEVIER SCI IRELAND LTD, 2004) Baltaci, AK; Sunar, F; Mogulkoc, R; Oztekin, EThis study aims at investigating how zinc deficiency and zinc application affect lipid peroxidation in bone tissue of ovariectomized rats. The study included 40 adult female rats of Sprague-Dawley species. Group 1 (n = 10): control group were fed with normal diet. Group 2 (n = 10): the group fed with normal diet after being ovariectomized. Group 3 (n = 10): the group fed with zinc-deficient diet for 6 weeks after ovariectomy. Group 4 (n = 10): the group which was given intraperitoneal zinc (3 mg/kg day zinc) in addition to normal diet for 6 weeks after ovariectomy. Malondialdehyde (MDA) and glutathione (GSH) levels were determined in erythrocyte, plasma and bone tissue. Group 3 had the highest plasma MDA levels compared to Groups 1, 2 and 4 (P < 0.05). These values were higher in Group 2 than in Groups 1 and 4 (P < 0.05). Bone and plasma MDA levels in Groups I and 4 were not different. Bone and erythrocyte GSH levels in Group 4 were higher than those in all other groups (P < 0.05). The lowest levels of bone and erythrocyte GSH levels were observed in Group 3 (P < 0.05). These values were higher in Group 2 when compared to those in Groups I and 3 (P < 0.05). This study demonstrate that zinc deficiency increased bone tissue damage in ovariectomized rats and that zinc supplementation prevented this damage. (C) 2004 Elsevier Ireland Ltd. All rights reserved.Öğe The effects of zinc deficiency and testosterone supplementation on leptin levels in castrated rats and their relation with LH, FSH and testosterone(MAGHIRA & MAAS PUBLICATIONS, 2005) Ozturk, A; Baltaci, AK; Mogulkoc, R; Oztekin, E; Kul, AAIM: The aim of this study was to investigate how zinc-deficiency and testosterone supplementation, both in combination and individually, affect plasma LH, FSH and leptin levels in castrated rats. DESIGN: Group 1, Control Group. Group 2, Castration Group. Group 3, Testosterone Group. Group 4, Zinc-deficient Group. Group 5, Testosterone, Zinc-deficient Group. Group 6, Zinc-deficient, Castration Group. Group 7, Testosterone, Castration Group. Group 8, Zinc-deficient, Testosterone, Castration Group. MEASUREMENTS: Plasma zinc, leptin, LH, FSH, free and total testosterone levels were measured. RESULTS: Group 2 had the highest levels of leptin and LH, besides having the highest FSH levels together with Group 6 (p < 0.01). Groups 5 and 8 had the lowest leptin levels (p < 0.01). Leptin levels in Groups 4 and 7 were higher than those in Groups 5 and 8, but lower than those in all other groups (p < 0.01). LH levels in Group 4 were not different than those in Groups 3, 5 and 8, but significantly lower than those in all other groups (p < 0.01). Free and total testosterone levels were higher in Group 4 than in castration groups that were not supplemented testosterone, but were lower in the former than in all others (p < 0.01). CONCLUSION: Plasma LH may be more effective than testosterone on plasma leptin and zinc can be an important mediator of the effect LH exercises on leptin.Öğe Etanercept treatment in the endotoxin-induced uveitis of rats(ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD, 2004) Avunduk, MC; Avunduk, AM; Oztekin, E; Baltaci, AK; Ozyazgan, Y; Mogolkoc, RThis study was conducted to investigate therapeutic value of a soluble tumor necrosis factor-alpha (TNF-alpha) receptor, etanercept, in a rat model of endotoxin-induced uveitis (EIU). Forty-two inbred male Lewis rats were divided into seven equal groups. 200 mug of Escherichia coli 055:1355 lipopolysaccharide, (LPS) was injected in one hind footpad of the Groups 2, 3, 4, 5, 6, and 7 rats. Group 5, 6, and 7 rats also received subcutaneous etanercept 24 hr prior to LPS injection at a dose of 0(.)4 mg kg(-1). Group 1 rats were used as controls. Eight, 24, and 48 hr after treatment clinical uvetis scores (miosis, iris hyperemia, and hypopyon) were assessed by a masked observer and the rats were euthanized. Neutrophil leukocytes, CD8 +, CD4 +, and CD45RO + cells in the anterior uveal tissue were counted either after hematoxylin-eosin or monoclonal antibody staining. TNF-alpha. levels were also measured in the aqueous humor samples by an ELISA method. Etanercept treatment significantly improved clinical uveitis scores at all examination points compared to the LPS injected animals. The improvement was almost complete expect for the miosis score, since no significant difference was detected between the controls and LPS + Etanercept treated animals at all examination points. Cell counts were also at significantly lower levels in LPS + Etanercept treated animals at all examination points, except for CD8 + and CD45RO + cell counts at 24 hr examination point. There was no significant difference between the controls and LPS + Etanercept treated animals at all examination points as with CD4 + and CD45RO + cell counts at 48 hr. Our data showed that etanercept had a definite effect on the treatment of EIU. Further studies should clarify its efficacy on clinical uveitis conditions. (C) 2004 Elsevier Ltd. All rights reserved.Öğe Hyperthyroidism causes lipid peroxidation in kidney and testis tissues of rats: Protective role of melatonin(MAGHIRA & MAAS PUBLICATIONS, 2005) Mogulkoc, R; Baltaci, AK; Oztekin, E; Aydin, L; Tuncer, IOBJECTIVE: The present study aimed at determining how 3-weeks intraperitoneal melatonin administration affected oxidative stress caused by experimental hyperthyroidism. MATERIALS AND METHODS: The study was conducted on 30 male rats of Spraque-Dawley species. The experimental animals were divided to 3 groups (control, hyperthyroidism and hyperthyroidism+melatonin). The supplementation was continued for 3 weeks after which the animals were sacrified and tissue malondyaldehyde (MDA) and glutathione (GSH) levels were determined. RESULTS: MDA levels in kidney and testis tissues in hyperthyroidism group were higher than those in control and hyperthyroidism+melatonin administered groups (p < 0.001) and levels in hyperthyroidism + melatonin administered group were higher than those in the control group (p < 0.001). The highest GSH levels were obtained in hyperthyroidism + melatonin-administered group (p < 0.001) and GSH levels in hyperthyroidism group were higher than those in the control group (p < 0.001). CONCLUSION: Results of the study demonstrate that hyperthyroidism induced by 3-weeks L-thyroxine administration increased oxidative stress in kidney and testis tissues and that although melatonin administration inhibited this stress to a certain extent, it could not bring the stress down to the level in controls.Öğe Melatonin prevents oxidant damage in various tissues of rats with hyperthyroidism(PERGAMON-ELSEVIER SCIENCE LTD, 2006) Mogulkoc, R; Baltaci, AK; Oztekin, E; Aydin, L; Sivrikaya, AImpairment of thyroid functions brings about pathological changes in different organs of body. Findings of in vivo and in vitro studies indicate that thyroid hormones have a considerable impact on oxidative stress. Melatonin reduces oxidative damage through its free radical eliminating and direct anti-oxidant effects. The present study was undertaken to determine how a 3-week period of intraperitoneal melatonin administration affected oxidative damage caused in experimental hyperthyroidism in rat. The experimental animals were divided into 3 groups (control, hyperthyroidism, hyperthyroidism+melatonin). Malondialdehyde (MDA) and glutathione (GSH) levels were determined in different tissues. MDA levels in cerebral, liver and cardiac tissues in hyperthyroidism group were significantly higher than those in control and hyperthyroidism+melatonin supplemented groups (p < 0.001). The highest GSH levels were observed in the group that was administered melatonin in addition to having hyperthyroidism (p < 0.001). These results show that hyperthyroidism increased oxidative damage in cerebral, hepatic and cardiac tissues of rat. Melatonin supplementation may also suppress oxidative damage. (c) 2006 Elsevier Inc. All rights reserved.Öğe Pinealectomy inhibits antioxidant system in rats with hyperthyroidism(MAGHIRA & MAAS PUBLICATIONS, 2005) Mogulkoc, R; Baltaci, AK; Aydin, L; Oztekin, E; Sivrikaya, AOBJECTIVE: Thyroid hormones regulate energy metabolism and act on the mitochondria, which is an important source of free radicals in the cell. Reactive oxygen types play a significant role in physiological mechanisms, but in excessive amounts they can cause oxidative damage in molecules. The aim of the present study was to determine levels of lipid peroxidation caused by induced hyperthyroidism in cerebral, hepatic and cardiac tissues of pinealectomized rats. METHODS: Experimental animals used in the study were allocated to three groups as general control group, hyperthyroidism-sham pinealectomy group and hyperthyroidism-pinealectomy group. GSH and MDA levels in cerebral, hepatic and cardiac tissues were evaluated at the end of the 3-week study period. RESULTS: It was found that MDA levels in cerebral, hepatic and cardiac tissues were the highest in hyperthyroidism and pinealectomy group and that these values were higher in hyperthyroidism-sham pinealectomy group than in the control group (p < 0.001). it was seen that tissue GSH levels significantly increased in hyperthyroidism-sham pinealectomy group (p < 0.001) and that the increase in hyperthyroidism and pinealectomy group was higher than the increase in the control group only (p < 0.001). CONCLUSION: Results of our study show that MDA and GSH levels in cerebral, hepatic and cardiac tissues increased due to hyperthyroidism and that the increase in MDA levels became more evident and GSH levels were significantly suppressed after pinealectomy.Öğe Short-term thyroxine administration leads to lipid peroxidation in renal and testicular tissues of rats with hypothyroidism(AKADEMIAI KIADO, 2005) Mogulkoc, R; Baltaci, AK; Oztekin, E; Ozturk, A; Sivrikaya, AThyroid dysfunction brings about pathological changes in different organs of the body. The aim of the present study was to examine how experimental hypothyroidism and additional short-term high-dose thyroxine administration (one-week) affected lipid peroxidation in renal and testicular tissues of rats. The study was carried out on 30 male Spraque-Dawley rats. The experimental animals were divided into 3 groups as control, hypothyroidism and hypothyroidism + thyroxine administration. Both malondialdehyde (MDA) and glutathione (GSH) levels were lower in renal and testicular tissues of the hypothyroidism group than the control and hypothyroidism + thyroxine administration groups and the levels in hypothyroidism + thyroxine administration group were higher than those in the control and hypothyroidism groups (p < 0.001). Results of the study demonstrate that hypothyroidism reduced oxidant stress in kidney and testis tissues, but short-term, high-dose thyroxine administration in addition to hypothyroidism increased oxidant stress in the same tissues of rats.Öğe Zinc supplementation ameliorates electromagnetic field-induced lipid peroxidation in the rat brain(TOHOKU UNIV MEDICAL PRESS, 2006) Bediz, CS; Baltaci, AK; Mogulkoc, R; Oztekin, EExtremely low-frequency (0-300 Hz) electromagnetic fields (EMFs) generated by power lines, wiring and home appliances are ubiquitous in Our environment. All populations are now exposed to EMF, and exposure to EMF may pose health risks. Some of the adverse health effects of EMF exposure are lipid peroxidation and cell damage in various tissues. This study has investigated the effects of EMF exposure and zinc administration on lipid peroxidation in the rat brain. Twenty-four male Sprague-Dawley rats were randomly allocated to three groups; they were maintained untreated for 6 months (control, n=8), exposed to low-frequency (50 Hz) EMF for 5 minutes every other day for 6 months (n=8), or exposed to EMF and received Zinc sulfate daily (3 mg/kg/day) intraperitoneally (n=8). We measured plasma levels of zinc and thiobarbituric acid reactive substances (TBARS), and levels of reduced glutathione (GSH) in erythrocytes. TBARS and GSH levels were also determined in the brain tissues. TBARS levels in the plasma and brain tissues were higher in EMF-exposed rats with or without zinc supplementation, than those in controls (p<0.001). In addition, TBARS levels were significantly lower in the zinc-supplemented rats than those in the EMF-exposed rats (p<0.001). GSH levels were significantly decreased in the brain and erythrocytes of the EMF-exposed rats (p<0.01), and were highest in the zinc-supplemented rats (p<0.001). Plasma zinc was significantly lower in the EMF-exposed rats than those in controls (p<0.001), while it was hi-hest in the zinc-supplemented rats (p<0.001). The present study suggests that long-term exposure to low-frequency EMF increases lipid peroxidation in the brain, which may be ameliorated by Zinc Supplementation.
