Person: KASIMAY ÇAKIR, ÖZGÜR
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KASIMAY ÇAKIR
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ÖZGÜR
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Publication Metadata only Estrogen Protects against Oxidative Multiorgan Damage in Rats with Chronic Renal Failure(TAYLOR & FRANCIS LTD, 2009) YEGEN, BERRAK; Kasimay, Oezguer; Sener, Goeksel; Cakir, Baris; Yueksel, Meral; Cetinel, Sule; Contuk, Gazi; Yegen, Berrak C.The impact of sex dimorphism on chronic renal failure (CRF)-induced oxidative multiorgan damage and the effects of estradiol (E-2) loss and E-2 supplementation on the progress of CRF were studied. Sprague-Dawley rats underwent 5/6 nephrectomy (CRF), and a group of female rats had bilateral ovariectomy (OVX), while the sham-operated rats had no nephrectomy or OVX. Rats received either estradiol propionate (50 mu g/kg/day) or vehicle for six weeks. Serum BUN levels were elevated in both male and female CRF groups treated with vehicle, while creatinine level was not significantly changed in the female CRF group. CRF-induced elevation in serum TNF-alpha of male rats was abolished when the animals were treated with E-2, while OVX exaggerated TNF-alpha response. In OVX and male rats with CRF, E-2 treatment reversed the malondialdehyde elevations in all the studied tissues (kidney, heart, lung, ileum, brain, liver, and gastrocnemius muscle), while depletion of glutathione in these tissues was prevented by E-2 treatment. Similarly, increased levels of myeloperoxidase activity, lucigenin chemiluminescence, and collagen in most of the tissues were reversed by E-2 treatment. The findings show that the extent of tissue injuries was relatively less in females, while ovariectomy exacerbated all the indices of oxidative injury. Moreover, the administration of E-2, with its potent anti-oxidant and anti-inflammatory effects, markedly improved CRF-induced systemic inflammatory outcomes in both male and female rats by depressing tissue neutrophil infiltration and modulating the release of inflammatory cytokines.Publication Metadata only Diet-supported aerobic exercise reduces blood endothelin-1 and nitric oxide levels in individuals with impaired glucose tolerance(ELSEVIER SCIENCE INC, 2010) YEGEN, BERRAK; Kasimay, Ozgur; Ergen, Nilay; Bilsel, Serpil; Kacar, Omer; Deyneli, Oguzhan; Gogas, Dilek; Akalin, Sema; Yegen, Berrak C.; Kurtel, HizirBACKGROUND: Impaired glucose tolerance (IGT) forms an intermediate stage in the natural history of diabetes mellitus. Insulin-resistant states might be associated with dysfunction of the vascular endothelium. OBJECTIVES: To determine the effects of chronic exercise and a low-calorie diet on plasma nitric oxide (NO) and endothelin-1 (ET-1) levels in patients with JOT and to elucidate the relationship between the oxidant stress markers and NO/ET-1 levels of blood before and after exercise. METHODS: Patients with IGT (n = 14) participated in a regular exercise program and exercised for 40 minutes each day, 3 days a week for 12 weeks. Physiological, anthropometric, and biochemical measurements were performed before, during the 6th week, and at the end of the program. RESULTS: There was a significant reduction in body mass index, body fat content, systolic and diastolic blood pressures, as well as NO and ET-1 concentrations after 12 weeks of exercise and diet program. Exercise training significantly elevated subjects' maximum oxygen consumption, whereas the resting metabolic rates of the patients did not change. The formation of thiobarbituric acid reactive substances were significantly reduced, whereas sulfhydryl groups were significantly increased on the 6th week (P < .05) and at the end of program (P < .01). CONCLUSION: Our results demonstrate that exercise, along with low-calorie diet, induced reductions in the plasma of both ET-1 and NO. Beneficial effects were observed on anthropometric measurements and plasma oxidant stress markers, indicating weight loss associated with exercise training and calorie restriction may effectively improve endothelial dysfunction in patients with IGT. (C) 2010 National Lipid Association. All rights reserved.Publication Metadata only Estrogen receptor agonists alleviate cardiac and renal oxidative injury in rats with renovascular hypertension(TAYLOR & FRANCIS INC, 2016) YEGEN, BERRAK; Kumral, Zarife Nigar Ozdemir; Kolgazi, Meltem; Ustunova, Savas; Cakir, Ozguer Kasimay; Cevik, Ozge Dagdeviren; Sener, Goksel; Yegen, Berrak C.Although endogenous estrogen is known to offer cardiac and vascular protection, the involvement of estrogen receptors in mediating the protective effect of estrogen on hypertension-induced cardiovascular and renal injury is not fully explained. We aimed to investigate the effects of estrogen receptor (ER) agonists on oxidative injury, cardiovascular and renal functions of rats with renovascular hypertension (RVH). Female Sprague-Dawley rats were randomly divided as control and RVH groups, and RVH groups had either ovariectomy (OVX) or sham-OVX. Sham-OVX-RVH and OVX-RVH groups received either ER agonist diarylpropiolnitrile (1 mg/kg/day) or ER agonist propyl pyrazole triol (1 mg/kg/day) for 6 weeks starting at the third week following the surgery. At the end of the 9(th) week, systolic blood pressures were recorded, cardiac functions were determined, and the contraction/relaxation responses of aortic rings were obtained. Serum creatinine levels, tissue malondialdehyde, glutathione, superoxide dismutase, catalase levels, and myeloperoxidase activity in heart and kidney samples were analyzed, and Na+, K+-ATPase activity was measured in kidney samples. In both sham-OVX and OVX rats, both agonists reduced blood pressure and reversed the impaired contractile performance of the heart, while ER agonist improved renal functions in both the OVX and non-OVX rats. Both agonists reduced neutrophil infiltration, lipid peroxidation, and elevated antioxidant levels in the heart, but a more ER-mediated protective effect was observed in the kidney. Our data suggest that activation of ER might play a role in preserving the function of the stenotic kidney and delaying the progression of renal injury, while both receptors mediate similar cardioprotective effects.Publication Metadata only Stress-induced multiple organ damage in rats is ameliorated by the antioxidant and anxiolytic effects of regular exercise(WILEY, 2010) YEGEN, BERRAK; Cakir, Baris; Kasimay, Oezguer; Kolgazi, Meltem; Ersoy, Yasemin; Ercan, Feriha; Yegen, Berrak C.Our aim was to investigate the effects of moderate load, regular swimming exercise on stress-induced anxiety, and associated oxidative organ injury. Male Sprague-Dawley rats (n = 48) were either kept sedentary or submitted to swimming exercise for 8 weeks. Rats were then divided as non-stressed, acute stress, and chronic stress groups. After acute or chronic stress (electric foot shocks) applications, rats were placed on a holeboard and the exploratory behavior was recorded to assess the anxiety. Rats were decapitated after the stress application. Acute and chronic stress induction led to increased serum cortisol levels as compared to non-stressed groups. Plasma aspartate aminotransferase levels that were elevated in sedentary rats with both stress exposures were lower in trained rats. Malondialdehyde levels and myeloperoxidase activity were increased in the cardiac muscle, liver, stomach, and brain of the stressed rats with a concomitant reduction in the glutathione levels, while stress-induced changes in malondialdehyde, myeloperoxidase, and glutathione levels were reversed in the trained animals. Exercise, which led to increased malondialdehyde and reduced glutathione levels in the skeletal muscle of the non-stressed rats, also protected against stress-induced oxidative damage. Regular exercise with its anxiolytic and antioxidant effects ameliorates stress-induced oxidative organ damage by a neutrophil-dependent mechanism. Copyright (C) 2010 John Wiley & Sons, Ltd.Publication Open Access Colitis-induced oxidative damage of the colon and skeletal muscle is ameliorated by regular exercise in rats: the anxiolytic role of exercise(WILEY, 2006-09-01) YEGEN, BERRAK; Kasimay, Ozgur; Guzel, Esra; Gemici, Ali; Abdyli, Asead; Sulovari, Admir; Ercan, Feriha; Yegen, Berrak C.Epidemiological studies have shown that exercise protects the gastrointestinal tract, reducing the risk of diverticulosis, gastrointestinal haemorrhage and inflammatory bowel disease, while many digestive complaints occurring during exercise are attributed to the adverse effects of exercise on the colon. In order to assess the effects of regular exercise on the pathogenesis of colitis, Sprague-Dawley rats of both sexes were either kept sedentary or given exercise on a running wheel (0.4 km h(-1), 30 min for 3 days week(-1)). At the end of 6 weeks, under anaesthesia, either saline or acetic acid (4%, 1 ml) was given intracolonically. Holeboard tests were performed for the evaluation of anxiety at 24 h before and 48 h after induction of colitis. Increased 'freezing time' in the colitis-induced sedentary group, representing increased anxiety, was reduced in the exercised colitis group (P < 0.05). On the third day following the colonic instillation, the rats were decapitated under brief ether anesthesia and the distal 8 cm of the colons were removed. In the sedentary colitis group, macroscopic and microscopic damage scores, malondialdehyde level and myeloperoxidase activity were increased when compared to the control group (P < 0.01-0.001), while exercise prior to colitis reduced all the measurements with respect to sedentary colitis group (P < 0.05-0.001). The results demonstrate that low-intensity, repetitive exercise protects against oxidative colonic injury, and that this appears to involve the anxiolytic effect of exercise, suggesting that exercise may have a therapeutic value in reducing stress-related exacerbation of colitis.