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Öğe The activities of tissue xanthine oxidase and adenosine deaminase and the levels of hydroxyproline and nitric oxide in rat hearts subjected to doxorubicin: protective effect of erdosteine(Elsevier Ireland Ltd, 2003) Fadillioglu, E; Yilmaz, HR; Erdogan, H; Sogut, SThe aim of this experimental study was to investigate the effects of erdosteine, an antioxidant agent, on doxorubicin (DXR)-induced cardio-toxicity through nitric oxide (NO) levels, collagen synthesis, xanthine oxidase (XO) and adenosine deaminase (ADA) activities in rats. Rats were treated with erdosteine (10 mg/kg b.wt. per day, orally) or saline starting 2 days before administrating a single dose of DXR (20 mg/kg i.p.) or saline. At the 10th day of the DXR administration, hearts were removed under anesthesia for biochemical measurements. Enzyme activities as well as OH-proline and NO levels were found to be significantly increased in DXR group compared with the control group. All of the parameters studied except ADA activity were decreased significantly approximating to the control levels upon erdosteine administration. In conclusion, erdosteine seems to be an alternative agent for protection of cardiac tissue against DXR-induced cardio-toxicity through its regulatory effect on XO activity and NO level. (C) 2003 Elsevier Ireland Ltd. All rights reserved.Öğe Changes in nitric oxide levels and antioxidant enzyme activities may have a role in the pathophysiological mechanisms involved in autism(Elsevier Science Bv, 2003) Sögüt, S; Zoroglu, SS; Özyurt, H; Yilmaz, HR; Özugurlu, F; Sivasli, E; Yetkin, ÖBackground: There is evidence that oxygen free radicals play an important role in the pathophysiology of many neuropsychiatric disorders. Although it has not been investigated yet, several recent studies proposed that nitric oxide (NO) and other parameters related to oxidative stress may have a pathophysiological role in autism. Methods: We assessed the changes in superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activities and thiobarbituric acid-reactive substances (TBARS) levels in plasma as well as NO levels in red blood cells (RBC) in patients with autism (n = 27) compared to age- and sex-matched normal controls (n = 30). Results: In the autistic group, increased RBC NO levels (p < 0.0001) and plasma GSH-Px activity (p < 0.0001) and unchanged plasma TBARS levels and SOD activity were detected. Conclusions: These findings indicate a possible role of increased oxidative stress and altered enzymatic antioxidants, both of which may be relevant to the pathophysiology of autism. (C) 2003 Published by Elsevier Science B.V.Öğe Cisplatin-induced acute renal failure is ameliorated by erdosteine in a dose-dependent manner(Wiley, 2004) Özyurt, H; Yildirim, Z; Kotuk, M; Yilmaz, HR; Yagmurca, M; Iraz, M; Sögüt, SThe aim of this study was to investigate the optimum dosage of erdosteine to ameliorate cisplatin-induced nephrotoxicity. Three different doses of erdosteine at 25, 50 and 75 mg kg(-1) were studied in rats. Intraperitoneal administration of 7 mg kg(-1) cisplatin led to acute renal failure, as indicated by kidney histology and increases in plasma creatinine and blood urea nitrogen (BUN) levels. At 5 days after cisplatin injection the BUN level was increased significantly from 15.1 +/- 4.3 to 126.7 +/- 152.6 mg dl(-1) and plasma creatinine levels increased from 0.37 +/- 0.005 to 1.68 +/- 1.9 mg dl(-1). When the rats were administered 50 and 75 mg kg(-1) erdosteine 24 h before cisplatin injection that was continued until sacrifice (total of 6 days), the BUN and creatinine levels remained similar to control levels and the grade of histology was similar. Erdosteine at doses of 50 and 75 mg kg(-1) ameliorates cisplatin-induced renal failure. The optimum dose of erdosteine may be 50 mg kg(-1) in this study. Copyright 2004 John Wiley Sons, Ltd.Öğe The effects of erdosteine on the activities of some metabolic enzymes during cisplatin-induced nephrotoxicity in rats(Academic Press Ltd- Elsevier Science Ltd, 2004) Yilmaz, HR; Iraz, M; Sogut, S; Ozyurt, H; Yildirim, Z; Akyol, O; Gergerlioglu, SCisplatin is one of the widely used chemothrapeutic agents. One of the major side effects of the drug is renal toxicity. The aims of the presented study was (1) to investigate the effect of cisplatin on some renal metabolic enzyme activities such as hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) in an experimental model of acute renal failure and (2) to examine the protective role of erdosteine, an expectorant agent which has also antioxidant properties on cisplatin-induced nephrotoxicity and the enzyme activities mentioned above. Female Wistar albino rats were divided into three groups: sham operation group (n = 6). cisplatin group (n = 9), erdostein + cisplatin group (n = 8). All the chemicals used were applied intraperitoneally. Hexokinase, G6PD, LDH, and MDH activities were determined in the kidney supernatant at the end of the surgical procedures. Spectrophotometric methods were used to determine the activities of above-mentioned enzymes in the kidney tissue. Hexokinase and G6PD activities were found to be increased in cisplatin group compared to control group. G6PD activities were found to be decreased in erdosteine + cisplatin group compared to cisplatin group. There were minimal changes in LDH and MDH activities of the two study groups compared with the control group. The results obtained suggested that the glucose metabolizing metabolic pathways of renal tissue were partially affected from cisplatin toxicity and erdosteine have some protective effects on these enzyme activities. (C) 2004 Elsevier Ltd. All rights reserved.Öğe The effects of ginkgo biloba extract on tissue adenosine deaminase, xanthine oxidase, myeloperoxidase, malondialdehyde, and nitric oxide in cisplatin-induced nephrotoxicity(Sage Publications Inc, 2006) Gulec, M; Iraz, M; Yilmaz, HR; Ozyurt, H; Temel, IThis study was carried out to determine if Ginkgo Biloba Extract (GBE or Egb 761) exerts a beneficial effect against cisplatin-induced renal failure in rats. Sprague Dawley rats were divided into four groups. The first group (control) received orally 1 mL/kg/day of 0.9% saline by an oral carrier vehicle on days 1 to 10. The second group was injected with 7 mg/kg cisplatin intraperitoneally (i.p.) on the fourth day, once only. The third group (vit E + cisplatin) was administered 10 mg/kg/day i.p. vit E on 1 to 10 days with one dose of i.p. cisplatin (7 mg/kg) injection on the fourth day. The fourth group (GBE + cisplatin) was given GBE orally at 100 mg/mL/kg started on the first day up to the tenth day with one dose of cisplatin (7 mg/kg) injection on the fourth day. Cisplatin was found to lead a statistically significant increase in plasma BUN and creatinine levels, as well as urine micro total protein (MTP) levels, leading to acute renal failure (ARF) in rats. Renal xanthine oxidase (XO) activities increased in all groups (statistically significant in cisplatin + GBE-treated rats; P < 0.001). Adenosine deaminase (AD) activities were increased in cisplatin-treated rats, and decreased in cisplatin + GBE-treated (P < 0.041) and cisplatin + vit E-treated (P < 0.005) rats, compared to controls. Malondialdehyde (MDA), nitric oxide (NO) levels and myeloperoxidase (MPO) activities were increased in the kidney tissue of cisplatin-treated rats. Vit E improved plasma creatinine and urine MTP levels, together with tissue MDA, NO levels, and MPO activities. But GBE had no statistically significant effect on those parameters. These results indicate that increased XO, AD and MPO activities, as well as MDA and NO levels play a critical role in cisplatin nephrotoxicity. GBE has been shown to protect against cisplatin-induced nephrotoxicity.Öğe In vivo evidence suggesting a role for purine-catabolizing enzymes in the pathogenesis of cisplatin-induced nephrotoxicity in rats and effect of erdosteine against this toxicity(Wiley, 2004) Sögüt, S; Kotuk, M; Yilmaz, HR; Ulu, R; Özyurt, H; Yildirim, ZThe aim of this experimental study was to investigate the possible role of adenosine deaminase (AD) and xanthine oxidase (XO) in the pathogenesis of cisplatin-induced nephrotoxicity and the effect of erdosteine in decreasing the toxicity. The intraperitoneal injection of cisplatin (7m kg(-1) body weight) induced a significant increase in plasma creatinine level and blood urea nitrogen (BUN), and plasma and damaged renal tissue activities of AD and XO in rats. Co-treatment with erdosteine (10 mg kg(-1) day(-1)) attenuated the increase in the plasma creatinine and BUN levels, and significantly prevented the increase in tissue and plasma AD and XO activities (P < 0.05). The results of this study revealed that XO and AD may play an important role in the pathogenesis of cisplatin-induced nephrotoxicity. The potent free radical scavenger erdosteine may have protective potential in this process and it will become a promising drug in the prevention of this undesired side-effect of cisplatin. but further studies are needed to illuminate the exact protection mechanism of erdosteine against cisptatin-induced nephrotoxicity. Copyright (C) 2004 John Wiley Sons, Ltd.Öğe Increased nitric oxide and superoxide dismutase levels in euthymic bipolar patients: Impact of past episodes(Federation Amer Soc Exp Biol, 2005) Gergerlioglu, HS; Savas, HA; Armutcu, F; Herken, H; Zoroglu, SS; Tutkun, H; Yilmaz, HR[Abstract Not Available]Öğe The protective effect of nebivolol on ischemia/reperfusion injury in rabbit spinal cord(Pergamon-Elsevier Science Ltd, 2004) Ilhan, A; Yilmaz, HR; Armutcu, F; Gurel, A; Akyol, OThe aim of this experimental study was to investigate whether nebivolol has protective effects against neuronal damage induced by spinal cord ischemia/reperfusion (I/R). Twenty-one rabbits were divided into three groups: group I (control, no I/R), group II (only I/R) and group III (I/R+nebivolol). Spinal cord ischemia was induced by clamping the aorta both below the left renal artery and above the aortic bifurcation. Seventy-two hours postoperatively, the motor function of the lower limbs was evaluated in each animal. The animals were sacrificed at 72 h, and histopathological and biochemical analyses were carried out in the lumbar spinal cords. The motor deficit scores in nebivolol group were different from I/R group at 72 h (3.25 0.70 vs. 1.75 +/- 1.28, p=0.01). I/R produced a significant increase in the superoxide dismutase (SOD), xanthine oxidase (XO), adenosine deaminase (ADA) and myeloperoxidase (MPO) activities in spinal cord tissue when compared with control group. Nebivolol treatment prevented the increase of all those enzymes activities produced by I/R. A significant decrease in spinal cord glutathione peroxidase (GSH-Px) level was seen in I/R group and nebivolol treatment prevented the decrement in the spinal cord tissue GSH-Px contents. On the other hand, I/R produced a significant increase in the spinal cord tissue malondialdehyde (MDA) and nitric oxide (NO) contents, this was prevented by nebivolol treatment. In conclusion, this study demonstrates a considerable neuroprotective effect of nebivolol on neurological, biochemical and histopathological status during periods of spinal cord I/R in rabbits. (C) 2004 Elsevier Inc. All rights reserved.Öğe Vitreoscilla hemoglobin renders Enterobacter aerogenes highly susceptible to heavy metals(Springer, 2004) Geckil, H; Arman, A; Gencer, S; Ates, B; Yilmaz, HRWhen expressed in heterologous microorganisms Vitreoscilla hemoglobin (VHb) acts as oxygen storage and causes a higher oxygen uptake. In this study, the effect of this protein on growth, sensitivity and antioxidant properties of Enterobacter aerogenes exposed to metal stress was investigated. The strain expressing VHb was more sensitive to mercury and cadmium as the minimal inhibitory concentration (MIC) for these metals was up to 2-fold lower in this strain than the host and the recombinant strain carrying a comparable plasmid. At lower concentrations than MIC, the metals partially limited growth and caused an inhibition proportional to metal concentration applied. The growth pattern of VHb expressing strain was also distinctly different from other two non-hemoglobin strains. The hemoglobin containing strain showed substantially higher superoxide dismuates (SOD) activity than the non-hemoglobin strains, while catalase levels were similar in all strains. All strains exposed to copper, however, showed similar MIC values, growth patterns, and SOD and catalase levels.
