Yazar "Atmaca M." seçeneğine göre listele

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    Differential effect of glutathione depletion on glycogenolysis in isolated rat hepatocytes mediated by ?-adrenoceptor agonists and glucagon
    (2005) Atmaca M.; Fry J.R.
    Glutathione (GSH) exerts a variety of cytoprotecive effects, but is readily depleted from cells under a variety of stressful stimuli. The impact of GSH depletion on receptor-mediated activity in rat hepatocytes has been studied with regard to glycogenolysis stimulated with a-adrenoceptor agonists or glucagon, which exert their actions through different signalling pathways. Depletion of GSH content (70%) by diethyl maleate had no effect on the redox status of the cells or on basal or glucagon-stimulated glycogenolysis, but significantly reduced the response to the a-adrenoceptor agonists adrenalin and phenylephrine. These results highlight the possible modulatory effects of GSH on receptor-mediated activity in hepatocytes.
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    Effect of exercise on blood antioxidant status and erythrocyte lipid perodixation: Role of dietary supplementation of vitamin E
    (1999) Kelle M.; Diken H.; Sermet A.; Atmaca M.; Tumer C.
    We tested the effects of moderate physical exercise on the blood antioxidant capacity and erythrocyte lipid peroxidation in 21 Wistar albino rats. Erythrocyte superoxide dismutase (SOD) activity increased significantly (p<0.05) in control exercised animals (C-Ex), but catalase activity did not change. SOD activity was decreased by dietary supplementation of vitamin E (p<0.05). In vitamin E supplemented group (E-Ex), catalase activity was reduced in comparison to C-Ex group. Total glutathione (total GSH) level was unaffected by the exercise. However, significant reduction was observed in reduced glutathione (GSH), whereas oxidized glutathione (GSSG) increased (p<0.01 and p<0.001, respectively). In E-Ex animals, total GSH and GSH were increased in comparison to C-Ex group. GSH/GSSG ratio decreased abnormally in both exercised groups (p<0.001). Serum cholesterol and uric acid levels increased significantly after exercise (p<0.05). The susceptibility of erythrocytes to in vitro peroxidation increased in C-Ex and E-Ex animals (p<0.001 and p<0.01, respectively). Elevated malondialdehyde (MDA) concentration in serum attained statistical significance after exercise. However, this elevation was prevented by vitamin E supplementation. Our results indicated that moderate intensive treadmill running exercise was sufficient to result in muscle damage and increases in the susceptibility of erythrocytes to in vitro peroxidation. In addition, dietary supplementation of vitamin E is able to minimize oxidative damage caused by exercise.
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    Effect of vitamin B6 intake on tissue zinc levels in the rat
    (1995) Sermet A.; Atmaca M.; Ulak G.; Diken H.; Ulak M.
    Effect of vitamin B6 intake on tissue zinc (Zn) concentrations was investigated in weanling, male Wistar albino rats (100-120 g). The animals were divided into two groups (n = 9) and treated for 4 weeks by intraperitoneal 5 mg/kg/day pyridoxine-HCl or placebo. The Zn content of the liver, spleen, right kidney and right femur were determined. Increases in weight gain in the control and Pyridoxine-treated group were 29.20 ± 1.43% and 51.20 ± 4.53%, respectively (P < 0.001). Dried weights of liver, kidney and femur were significantly higher than those of control group (p < 0.01; p < 0.02; p < 0.001, respectively). No significant difference was observed between the serum Zn concentrations of the experimental and control group (P > 0.05). The Zn content of the liver, spleen, kidney and femur for both total and dry weight per gram of organ weight were significantly higher in the experimental group compared to controls. These findings suggested that pyridoxine affects Zn metabolism in young rats.
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    Influence of zinc on imipenem susceptibility of Pseudomonas aeruginosa
    (1996) Atmaca S.; Gul K.; Ulak G.; Cicek R.; Atmaca M.
    The influence of zinc on imipenem susceptibility of Pseudomonas aeruginosa was investigated. In this study, two different amounts of zinc containing media were used, the first of which was Oxoid MHA containing 0.45 ?g/ml zinc, and the second Oxoid MHA supplemented with zinc-acetate, 64 times as much zinc as the first media. The percentage of P. aeruginosa isolates resistant to imipenem significantly increased (P < 0.001) in zinc-supplemented media, whereas the activity of ceftazidime against P. aeruginosa isolates was similar in both media.