Browsing by Author "Uysal, N"

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Serum IGF-1 levels correlate negatively to liver damage in diabetic rats
    Aksu, I; Baykara, B; Kiray, M; Gurpinar, T; Sisman, AR; Ekerbicer, N; Tas, A; Gokdemir-Yazar, O; Uysal, N
    Diabetes and insulin resistance frequently cause liver damage. Diabetes also causes reduction in liver and blood IGF-1 levels. We investigated the relation between liver damage and IGF-1 levels in diabetic rats. Fourteen Wistar albino rats were divided into control and diabetic groups. Diabetes was induced by streptozotocin. Rats were sacrificed for biochemical and histologic examinations 2 weeks after streptozotocin injection. Serum and liver IGF-1 levels were decreased, liver malondialdehyde (MDA) levels were increased, glutathione peroxidase (GPx) enzymes activities were decreased and serum alanine aminotransferase (ALT) levels were increased in diabetic group. Microscopic examination of liver revealed that normal tissue organization was disrupted in streptozotocin-induced diabetic rats. There was a strongly positive correlation between blood glucose levels and liver injury, and blood and liver IGF-1 levels. There was a strongly negative correlation between blood IGF-1 levels and hepatic injury. Our results suggest that reduction of blood IGF-1 levels correlates with hepatic injury and circulating IGF-1 levels may have predictive value for determining hepatic damage that results from diabetes. In addition, circulating IGF-1 levels are correlated with glutathione levels and the oxidative stress status of diabetic rat liver.
  • No Thumbnail Available
    Item
    The Histologic Evaluation of Atorvastatin and Melatonin Treatment on Oxidative Stress and Apoptosis of Diabetic Rat Pancreas
    Gürpinar, T; Ekerbiçer, N; Uysal, N; Barut, T; Tarakçi, F; Tuglu, MI
    In the diabetic state, there is an enhanced oxidative stress due to excessive production of reactive oxygen compounds and decreased bioavailability of nitric oxide. Antioxidant treatment has been used to prevent oxidative damage in diabetes. The objective of the present study was to explore the effects of atorvastatin (AT) and melatonin (MLT) on oxidative stress in diabetic rat pancreas. We also assessed nitric oxide synthase (NOS) activity and apoptosis. Diabetes was induced by an alkylating agent steptozotocin (STZ, 55 mg/kg, IP). Six weeks later rats were divided into five groups: STZ-induced diabetic group received atorvastatin (STZ+AT), STZ-induced diabetic group received melatonin (STZ+MLT) and STZ-induced diabetic group received atorvastatin and melatonin (STZ+AT+MLT). The vehicle-treated non-diabetic (CT) and diabetic group (STZ-CT) served as normoglycemic and diabetic controls. AT was given 8 mg/kg orally and MLT was given 10 mg/kg/IP once a day for 2 weeks beginning from the sixth week. Pancreatic tissue was examined by immunohistochemical methods. Although no significant difference was observed with respect to antioxidant status, NOS activity was tended to be higher in the untreated diabetic rats than in the treated rats. We observed that AT and MLT treatment improved the histopathological changes including apoptosis and oxidative stress in diabetic pancreas.
  • No Thumbnail Available
    Item
    Statins reduce testicular and ocular VEGF: A potential compromise to microcirculation
    Ekerbicer, N; Gurpinar, T; Sisman, AR; Guvendi, G; Camsari, UM; Uysal, N
    Microcirculation has great importance in eye and testicular tissue and is necessary to have adequate and appropriate amount of angiogenesis. It is known that high levels of Vascular Endothelial Growth Factor (VEGF) trigger uncontrolled angiogenesis, whereas inadequate VEGF can lead to decreased tissue perfusion and oxygenation. The aim of this study was to investigate effects of VEGF in testicular and ocular tissues in both nondiabetic and diabetic rats treated by statin. Atorvastatin (10 mg/kg daily given by orally gavage) was administered for two weeks. Diabetes was induced by streptozotocin, (STZ, 45 mg/kg/ip) in diabetic group's rats. Two weeks later from STZ injection, atorvastatin treatment was initiated in diabetic group. VEGF levels were measured by using ELISA. The VEGF levels were decreased in vitrous, ocular and testicular tissues of all statin-administered rats. In diabetic group VEGF levels were found to be decreased in testicular tissue and increased in ocular tissues. Conclusion: Statin use decreased in VEGF levels of testicular and ocular tissues in diabetic and non-diabetic rats. Statin treatment (anti-VEGF effect) had a protective effect in the development of diabetic retinopathy, yet statins may have a negative impact on tissues that depend on microcirculation by reducing VEGF levels. Further research is needed for statins' microcellular effects.
  • No Thumbnail Available
    Item
    The Effects of the Melatonin Treatment on the Oxidative Stress and Apoptosis in Diabetic Eye and Brain
    Gürpinar, T; Ekerbiçer, N; Uysal, N; Barut, T; Tarakçi, F; Tuglu, MI
    Oxidative stress plays an important role in the development of complications in diabetes mellitus. Antioxidant therapy has been thought to decrease oxidative stress. The objective of the present study was to explore the effects of melatonin (MLT) on oxidative stress in diabetic rat eye and brain tissue by using immunohistochemical methods. Diabetes was induced by streptozotocin, (STZ, 55 mg/kg/i.p) in adult rats. MLT was given 10 mg/kg/i.p once a day for 2 weeks beginning from the sixth week. Six weeks later, rats were divided into three groups: control (CR), STZ-induced diabetic (STZ), and STZ-induced diabetic group received melatonin (STZ+MLT). Although no significant difference was observed with respect to antioxidant status, NOS activity tended to be higher in the untreated diabetic rats than in the treated rats. It was observed that MLT treatment improved the histopathological changes including apoptosis and oxidative stress in brain and eye in diabetic rat.
  • No Thumbnail Available
    Item
    Combined Treatment with Progesterone and Magnesium Sulfate Positively Affects Traumatic Brain Injury in Immature Rats
    Uysal, N; Baykara, B; Kiray, M; Cetin, F; Aksu, I; Dayi, A; Gurpinar, T; Ozdemir, D; Arda, MN
    AIM: It is well known that head trauma results in damage in hippocampal and cortical areas of the brain and impairs cognitive functions. The aim of this study is to explore the neuroprotective effect of combination therapy with magnesium sulphate (MgSO4) and progesterone in the 7-days-old rat pups subjected to contusion injury. MATERIAL and METHODS: Progesterone (8 mg/kg) and MgSO4 (150 mg/kg) were injected intraperitoneally immediately after induction of traumatic brain injury. Half of groups were evaluated 24 hours later, the remaining animals 3 weeks after trauma or sham surgery. Anxiety levels were assessed with open field activity and elevated plus maze; learning and memory performance were evaluated with Morris Water maze in postnatal 27 days. RESULTS: Combined therapy with progesterone and magnesium sulfate significantly attenuated trauma-induced neuronal death, increased brain VEGF levels and improved spatial memory deficits that appear later in life. Brain VEGF levels were higher in rats that received combined therapy compared to rats that received either medication alone. Moreover, rats that received combined therapy had reduced hipocampus and prefrontal cortex apoptosis in the acute period. CONCLUSION: These results demonstrate that combination of drugs with different mechanisms of action may be preferred in the treatment of head trauma.
  • No Thumbnail Available
    Item
    Relationship between circulating IGF-1 levels and traumatic brain injury-induced hippocampal damage and cognitive dysfunction in immature rats
    Ozdemir, D; Baykara, B; Aksu, I; Kiray, M; Sisman, AR; Cetin, F; Dayi, A; Gurpinar, T; Uysal, N; Arda, MN
    It is well known that traumatic brain injury (TBI) induces the cognitive dysfunction resulting from hippocampal damage. In the present study, we aimed to assess whether the circulating IGF-I levels are associated with cognition and hippocampal damage in 7-day-old rat pups subjected to contusion injury. Hippocampal damage was examined by cresyl violet staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Spatial memory performance was assessed in the Morris water maze. Serum IGF-1 levels decreased in both early and late period of TBI. Decreased levels of serum IGF-1 were correlated with hippocampal neuron loss and spatial memory deficits. Circulating IGF-1 levels may be predictive of cognitive dysfunction resulted from hippocampal damage following traumatic injury in developing brain. Therapy strategies that increase circulating IGF-1 may be highly promising for preventing the unfavorable outcomes of traumatic damage in young children. (C) 2011 Elsevier Ireland Ltd. All rights reserved.
  • No Thumbnail Available
    Item
    An anxiolytic drug buspirone ameliorates hyperglycemia and endothelial dysfunction in type 2 diabetic rat model
    Cavusoglu, TG; Dariverenli, E; Vural, K; Ekerbicer, N; Ulman, C; Ölmez, E; Uysal, N
    Objectives: Type 2 diabetes is a common metabolic disease and anxiety disorders are very common among diabetics. Buspirone is used in the treatment of anxiety, also having blood glucose-lowering effects. The aim of the study was to investigate the effects of buspirone on the glucose and lipid metabolism as well as vascular function in type 2 diabetic rats. Methods: A type 2-diabetic model was induced through a high-fat diet for eight weeks followed by the administration of low-dose streptozotocin (35 mg/kg, intraperitoneal) in rats. Buspirone was given at two different doses (1.5 mg/kg/d and 5 mg/kg/d) and combined with metformin (300 mg/kg/d). The fasting glucose and insulin levels, lipid profile were analyzed, and vascular response measured from the thoracic aorta was also evaluated. Results: Both doses of buspirone caused a significant improvement in fasting blood glucose levels. In particular, the buspirone treatment, combined with metformin, improved endothelial dysfunction and was found to be correlated with decreased nitrate/nitrite levels. Conclusions: Buspirone may be effective in the treatment of type 2 diabetes, either alone or in combination with other treatments, particularly in terms of endothelial dysfunction, inflammation and impaired blood glucose, and insulin levels.