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Öğe Changes in tyrosine hydroxylase activity, adrenomedullin (ADM) and total RNA levels by treatment of organoselenium compounds in rat hypothalamus exposed to 7, 12-dimethylbenzanthracene (DMBA)(2010) Ozdemir I.; Talas Z.S.; Gok Y.; Ates B.; Yilmaz I.The effects of synthetic organoselenium compounds (Se I and Se II) on the activity of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis as well as adrenomedullin (ADM) and total RNA levels were determined in the hypothalamus of adult rats exposed to DMBA (7,12-dimeuiylbenz[a] anthracene). DMBA, an organic environmental pollutant, is a polycyclic aromatic hydrocarbon that can induce a range of toxic effects and stress in rats. Selenium is an essential trace element, which interacts with antioxidants, and has anticancer and antihypertensive properties. TH is an aromatic amino acid hydroxylase whose activity is elevated in response to a range of stress inducers. TH activity is normally regulated by negative feedback in catecholamine biosynthesis. ADM is an abundantly present peptide in a broad range of normal tissues including adrenal medulla, lungs, kidneys and brain. Plasma ADM levels are elevated in a number of diseases including essential hyptertension and chronic renal failure. The antioxidant properties of ADM offer protection against organ damage induced by high blood pressure, ischemia and aging. DMBA treatment increased the TH activity and ADM level in the hypothalamus. These increases were found to be inhibited by Se I and Se II treatments. These studies demonstrate that synthetic organoselenium compounds can suppress DMBA-induced stress-related changes in the rat hypothalamus. Therefore, the antioxidant and antihypertensive effects of Se I and Se II may have important effects in the maintainance of homeostasis. © by PSP.Öğe The effects of synthetic organoselenium compounds on nitric oxide in DMBA - Induced rat liver(Triveni Enterprises, 2009) Talas Z.S.; Bayraktar N.; Ozdemir I.; Gok Y.; Yilmaz I.DMBA (7,12-dimethylbenz[a]anthracene) is known to generate DNA-reactive species during their metabolism, which may enhance oxidative stress in cells. Since selenium is known as a non-enzymic antioxidant, health problems induced by many environmental pollutants, have stimulated the evaluation of relative antioxidant potential of selenium and synthetic organoselenium compounds. Therefore, we aimed to evaluate chemopreventive potential of synthetic organoselenium compounds by monitoring level of liver nitric oxide. In this study, adult female Wistar rats were treated with DMBA and the novel organoselenium compounds (Se I) and (Se II) in the determined doses. DMBA-induced in rats, the effects of organoselenium compounds on nitric oxide levels in rat liver was studied. In this study, it has been observed a statistically significant increase in (Nitric Oxide) levels for the liver of rat exposed to DMBA (p<0.05). However with administration of Se I and Se II there was a statistically significant decrease in NO levels (p<0.05). The ability of the organoselenium compounds to prevent oxidative damage induced by DMBA in rat livers was rationalized. Protection against nitric oxide measured in Se I and Se II treated groups were provided by synthesized organoselenium compounds. Se I and Se II both provided chemoprevention against DMBA-induced oxidative stress in rat liver. © Triveni Enterprises.Öğe Modulation of DMBA-induced biochemical changes by organoselenium compounds in blood of rats(2007) Ozdemir I.; Selamoglu Z.; Ates B.; Gok Y.; Yilmaz I.The protective role of two synthetic organoselenium compounds 1-isopropyl-3-methylbenzimidazole-2-selenone (SeI) and 1, 3-di-p-methoxybenzylpyrimidine-2-selenone (SeII) was examined against the 7,12-dimethylbenz[a]anthracene (DMBA)-induced changes in biochemical parameters in blood of rats. Albino Winstar rats (150-200 g body wt) were treated with single dose of DMBA (50 mg/kg body wt) and organoselenium compounds (25 ?mol/kg) for 4 weeks at two days internal. Blood was taken from the anaesthetized rats ventricle from their hearts for biochemical analysis. Administration of DMBA resulted in elevation of urea, uric acid and creatinine levels as well as AST, ALT and LDH activities and decrease in levels of total proteins, albumin and globulin. SeI and SeII caused a significant (p<0.05) decrease in urea, uric acid and creatinine levels and alanine aminotransferase (ALT); aspartate aminotransferase; (AST) and lactate dehydrogenase (LDH) activities and significantly increased the levels of total protein and albumin (p<0.05). These organoselenium compounds are likely to be beneficial in human health.Öğe Polyimides from a novel monomer 3,6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium(II) for a catalytic application(Springer New York LLC, 2004) Seckin T.; Koytepe S.; Ozdemir I.; Giirbiiz N.; Çetinkaya B.Tricyclic heteroaraomatic dye-based monomer containing NMe2 units, 6-bis(dimethylamino)acridine(p-cymene)dichlororuthenium (II), was used to prepare novel polyimides via a one-stage solution polycondensation due to their stability under a variety of oxidative and reductive conditions. The Ru(II) complex monomer was synthesized starting from [RuCl2 (p-cymene)]2 and 3,6-bis(dimethylamino)acridine. A series of stable polyimides was synthesized from the Ru(II) complex of 3,6-e/5(dimethylamino)acridine and various aromatic dianhyrides. The polymers had inherent viscosities ranging from 1.72 to 2.11 dL/g and were soluble in polar solvents. The glass transition temperatures were 192-278 °C, and the 10% weight loss temperatures were above 503-635 °C. Ruthenium-substituted polyimides were tested for catalytic activity in the furan formation reaction of (Z)-3-methylpent-2-en-4-yn-l-ol. The polymeric catalyst was added to (Z)-3-methylpent-2-en-4-yn-l-ol without a solvent and the pure furan was isolated by distillation under reduced pressure. The conversion of the starting, enynol, was determined by gas chromatography (GC). © 2004 Springer Science+Business Media, Inc.Öğe Role of propolis on oxidative stress in various tissues of fish(Parlar Scientific Publications, 2014) Aldemir O.S.; Selamoglu Z.; Gulhan M.F.; Cakir O.; Ozdemir I.; Dastan S.D.; Dogan H.The aim of this study was to investigate the therapeutic effects of propolis on biochemical parameters in tissues of rainbow trout (Oncorhynchus mykiss) exposed to Cypermethrin. Cypermethrin is a potential toxic pollutant that directly threats the aquatic ecosystems and environment. Sublethal Cypermethrin concentration of 0.0082 ppm was applied to the fish for 96 h. Propolis is a natural product collected from plants by honey bees. Its polyphenolic components, caffeic acid derivatives and flavonoids in particular, are matter of interest because of their strong antioxidant properties. Therapeutic concentration of propolis has been determined as 10 ppm in a previous study. Herein, malondialdehyde (MDA) levels and catalase (CAT) activities were determined in spleen and heart tissues of rainbow trouts. Results showed that CAT activities and MDA levels increased (P?0.001) in tissues of fish exposed to Cypermethrin compared to control group. CAT activities and MDA levels in the tissues of fish decreased in cyperme-thrin+propolis group (P?0.001) compared to Cypermethrin group. Propolis (10 ppm) on the tissues of the rainbow trout showed significant therapeutic effects. Propolis may serve as an antitoxic agent against pesticide toxicity to aquatic animals.
