Person: KABASAKAL, LEVENT
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KABASAKAL
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LEVENT
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Publication Metadata only Protective effects of resveratrol on hepatic ischemia reperfusion injury in streptozotocin-induced diabetic rats(SPRINGER, 2019) ELÇİOĞLU, HATİCE KÜBRA; Aktas, Hanife Serife; Ozel, Yahya; Ahmad, Sarfraz; Pence, Halime Hanim; Ayaz-Adakul, Betul; Kudas, Ilyas; Tetik, Sermin; Sekerler, Turgut; Canbey-Goret, Ceren; Kabasakal, Levent; Elcioglu, Hatice KubraResveratrol (RSV) is a natural polyphenolic compound having antioxidant effects. This study was designed to investigate the protective effects of resveratrol against oxidative stress in hepatic ischemia-reperfusion (I/R) injury in streptozotocin (STZ)-induced diabetic rats. STZ was injected intraperitonally (i.p.) to 18 Sprague-Dawley albino rats, which were divided into three groups, each having six rats. First group was non-treated diabetic group (D), second diabetic group was subjected to 30 min of hepatic ischemia followed by a 45-min reperfusion period (D + I/R), and third diabetic group was subjected to 30 min of hepatic ischemia followed by a 45-min reperfusion period and treated with 20 mg/kg/day oral RSV before 30 min I/R injury (D + I/R + RSV). At the end of the experimental period, animals were decapitated, and blood samples were collected to determine tissue tumor necrosis factor-alpha (TNF-alpha) levels. Liver and lung tissue samples were obtained for the evaluation of biochemical parameters including malondialdehyde (MDA) and glutathione (GSH) levels and histopathological examinations. Compared to control, I/R injury resulted in decreases in GSH levels and increases in MDA levels. Tissue TNF-alpha levels were also increased in the D + I/R group compared to D group. Treatment with RSV prevented the alterations on biochemical parameters and histopathological changes induced by I/R. We demonstrate that in diabetic rats, hepatic I/R injury is associated with an augmented inflammatory response and oxidative stress, while RSV pre-treatment significantly decreased these responses. Larger clinical studies are desirable to determine the exact role(s) of RSV on hepatic I/R injury among diabetic subjects.Publication Metadata only Protective effect of aqueous garlic extract against renal ischemia/reperfusion injury in rats(MARY ANN LIEBERT, INC, 2005) ŞENER, GÖKSEL; Kabasakal, L; Sehirli, O; Cetinel, S; Cikler, E; Gedik, N; Sener, GOxygen free radicals are important components involved in pathophysiological tissue alteration observed during ischemia/reperfusion (I/R). This study was designed to determine the possible protective effect of aqueous garlic extract (AGE) on renal I/R injury. Wistar albino rats were unilaterally nephrectomized and subjected to 45 minutes of renal pedicle occlusion followed by 6 hours of reperfusion. AGE (I mL/kg, i.p., corresponding to 500 mg/kg) or vehicle was administered twice: 15 minutes prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, rats were killed by decapitation. Kidney samples were taken for histological examination or determination of levels of free radicals; renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Renal tissue collagen content, as a fibrosis marker, was also determined. Creatinme and urea concentrations in blood were measured for the evaluation of renal function. The results revealed that I/R-induced nephrotoxicity, as evidenced by increases in blood urea and creatinine levels, was reversed by AGE treatment. The levels of free radicals, as assessed by the nitro blue tetrazolium test, were increased. Moreover, the decrease in GSH levels and the increases in MDA levels and MPO activity induced by I/R indicated that renal injury involves free radical formation. Treatment of rats with AGE (1 mL/kg) restored the reduced GSH levels, while it decreased free levels of radicals and MDA as well as MPO activity. Collagen contents of the kidney tissues increased by I/R were reversed back to the control levels with AGE. Since AGE administration reversed these oxidant responses and improved renal function and damage at the microscopic level, it seems likely that AGE protects kidney tissue against I/R-induced oxidative damage.Publication Metadata only Thalidomide attenuates learning and memory deficits induced by intracerebroventricular administration of streptozotocin in rats(TAYLOR & FRANCIS LTD, 2013) ELÇİOĞLU, HATİCE KÜBRA; Elcioglu, H. K.; Kabasakal, L.; Alan, S.; Salva, E.; Tufan, F.; Karan, M. A.Neuroinflammatory responses caused by amyloid beta (A beta) peptide deposits are involved in the pathogenesis of Alzheimer's disease (AD). Thalidomide has a significant anti-inflammatory effect by inhibiting TNF-alpha, which plays role in A beta neurotoxicity. We investigated the effect of thalidomide on AD-like cognitive deficits caused by intracerebroventricular injection of streptozotocin (STZ). Intraperitoneal thalidomide was administered 1 h before the first dose of STZ and continued for 21 days. Learning and memory behavior was evaluated on days 17, 18 and 19, and the rats were sacrificed on day 21 to examine histopathological changes. STZ injection caused a significant decrease in the mean escape latency in passive avoidance and decreased improvement of performance in Morris water maze tests. Histopathological changes were examined using hematoxylineosin and Bielschowsky staining. Brain sections of STZ treated rats showed increased neurodegeneration and disturbed linear arrangement of cells in the cortical area compared to controls. Thalidomide treatment attenuated significantly STZ induced cognitive impairment and histopathological changes. Thalidomide appears to provide neuroprotection from the memory deficits and neuronal damage induced by STZ.Publication Metadata only Changes in caveolin-1 expression and vasoreactivity in the aorta and corpus cavernosum of fructose and streptozotocin-induced diabetic rats(ELSEVIER, 2010) ELÇİOĞLU, HATİCE KÜBRA; Elcioglu, Kuebra H.; Kabasakal, Levent; Cetinel, Sule; Conturk, Gazi; Sezen, Sena F.; Ayanoglu-Dulger, GuelHyperglycemia is a common defining feature in the development of endothelial dysfunction which plays a key role in the pathogenesis of both type 1 and type 2 diabetes. Caveolin-1 is the main structural component of caveolae which might be involved in the pathophysiology of macrovascular complications of diabetes. In this study we aimed to observe the effect of caveolin-1 on functional responses of aorta and corpus cavernosum in the streptozotocin and fructose-induced diabetes groups. Type 1 diabetes was induced by intraperitoneal administration of streptozotocin (60 mg/kg),. Type 2 diabetes by adding fructose in the rat's drinking water (10% (w/v)) for 8 weeks. For insulin treatment; rats were treated with insulin (6 U/kg) for 8 weeks. In Type I and Type II diabetic groups the contractile responses of corpus cavernosum strips to phenylephrine (EC50:1.82 x 10(-5) M;1.47 x 10(-5) M, respectively)and relaxation responses to acetylcholine (EC50:7.5 x 10(-5) M;4.48 x 10(-5) M, respectively)were significantly impaired. Contractile responses of aortic-strips to phenylephrine in diabetic groups were markedly decreased (EC50:3.7. 10(-7) M;2.61. 10(-7) M respectively) and dose-dependent relaxation responses to acetylcholine were also attenuated (EC50:3.23 . 10(-6)M; 2.0. 10(-6)M respectively). Treatment with insulin improved the functional responses in the aorta and corpus cavernosum. Protein expression of caveolin-1 was increased in the aorta and corpus cavernosum of the diabetic groups, but this increase seen in the streptozotocin group was more significant than the fructose group. Our findings indicate that an attenuation of the functional responses in both diabetes groups were probably associated with an enhanced expression of caveolin-1, and therefore a decrease in the eNOS activity with a concomitant decrease in NO synthesis. (C) 2010 Elsevier B.V. All rights reserved.Publication Metadata only Ischemic colitis of the colon in streptozotocin-induced diabetic rats(SPRINGER, 2018) ELÇİOĞLU, HATİCE KÜBRA; Ozel, Yahya; Elcioglu, H. Kubra; Cevikelli, Z. Ayca; Kudas, Ilyas; Ahmad, Sarfraz; Uzun, Hafize; Topal, Cumhur; Aktas, Serife; Kabasakal, LeventThis study focuses on two inflammatory diseases, viz., diabetes mellitus (DM) that causes serious complications such as retinopathy, nephropathy, and neuropathy, and ischemic colitis which is evoked by DM. Ischemic colitis originates from the reduction in mesenteric blood flow to the colon with existence of the occlusive or non-occlusive reasons. Our study objective was to provide early diagnostic approach for ischemic colitis in streptozotocin (STZ)-induced diabetic rats. Sprague-Dawley rats were divided into four groups: (i) control use of 0.1 M citrate buffer, the solvent of streptozotocin (C), (ii). induced ischemia (I), (iii) rats subjected to 60 mg/kg STZ intraperitoneally to induce type 1 diabetes (D) (48 h after STZ injection, blood glucose levels >200 mg/dl were considered as diabetic), and (iv) diabetic rats subjected to intestinal ischemia (D+I). The third diabetic group (D) was not operated. At the end of the experimental period, rats were sacrificed, C-reactive protein (CRP) and calprotectin levels were measured in the serum and colon tissue specimens. Tissue specimens were also analyzed histologically. We found that serum and colon calprotectin levels were elevated in the D+I group compared to the D and/or I group alone, but relatively calprotectin levels increased in I as compared to C group in colon tissues. CRP levels were significantly increased with ischemic colitis in diabetes, while colon CRP levels were decreased. These results provide evidence for the existence of inflammation in the STZ-induced diabetic rats with ischemic colitis. In conclusion, our measurements of serum calprotectin levels of STZ-induced diabetic rats with ischemic colitis provide a practical approach for an early diagnosis of ischemic colitis. Furthermore, these biochemical analyses correlate well with the histopathologic findings of STZ-induced diabetic rats with ischemic colitis. Future studies would be desirable to further strengthen the role of calprotectin in the early diagnosis of ischemic colitis in diabetics clinical settings.Publication Metadata only The Effects of Riluzole on Neurological, Brain Biochemical, and Histological Changes in Early and Late Term of Sepsis in Rats(ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009) ERCAN, FERİHA; Toklu, Hale Z.; Uysal, Meral Keyer; Kabasakal, Levent; Sirvanci, Serap; Ercan, Feriha; Kaya, MehmetObjective. One of the underlying mechanisms of sepsis is thought to be the oxidative damage due to the generation of free radicals. Glutamate, the major excitatory amino acid in the brain, is known to play an important role in blood brain barrier (BBB) permeability, brain edema, and oxidative damage in pathological conditions. Riluzole, a glutamate release inhibitor, has been shown to have neuroprotective effects in several animal models. The aim of our study was to investigate the putative protective effect of riluzole against sepsis-induced brain injury. Methods. Sepsis was induced by cecal ligation and puncture in Wistar albino rats. Sham operated (control) and sepsis groups received either saline or riluzole (6 mg/kg, s.c.) 30 min after the surgical procedure, and every 12 h as continuing treatment. The effect of riluzole on the survival rate, weight loss, fever, leukocyte count, brain edema, BBB permeability, oxidative damage, and histological observations were evaluated for early (6 h) and late (48 h) phase of sepsis. Results. Riluzole, when administered 6 mg/kg s.c., diminishes the sepsis-induced augmentation in weight loss, body temperature, brain edema, increase in BBB permeability, oxidative damage, and brain injury that is observed histologically. Besides increasing the survival rate in sepsis, it has also improved neurological examination scores and the prognosis of the disease. Conclusion. According to the results of this study, riluzole appears to have a protective effect for sepsis-induced encephalopathy. (C) 2009 Elsevier Inc. All rights reserved.Publication Metadata only A study comparing the effects of rosiglitazone and/or insulin treatments on streptozotocin induced diabetic (type I diabetes) rat aorta and cavernous tissues(ELSEVIER, 2011) ÇELİKEL, ÇİĞDEM; Elcioglu, H. Kubra; Kabasakal, Levent; Ozkan, Naziye; Celikel, Cigdem; Ayanoglu-Dulger, GulOur aim was to investigate the role of oxidative stress and inflammation on the functional and biochemical changes caused by hyperglycemia in the aorta and corpus cavernosum tissues of streptozotozin diabetic rats and to determine if rosiglitazone and/or insulin treatment has any preventive effect on organ dysfunction. Wistar Albino rats were divided into 2 groups. I) Control group: a) Vehicle, 0.1 M citrate buffer, the solvent of streptozotocin injected intraperitoneally (i.p) and b) Rosiglitazone group: (4 mg/kg/day, i.p.) for 8 weeks. II) Diabetic group: streptozotocin (60 mg/kg) was administered i.p. to induce diabetes. 48 h after streptozotocin injection, animals were divided into 4 subgroups (n = 6 for each group); a) no treatment group (D), b) treated with rosiglitazone (4 mg/kg/day) (DR), c) treated with insulin (6 U/kg/day) (DI) and d) treated with insulin and rosiglitazone (DRI) for 8 weeks. At the end of the experimental period, animals were decapitated and tissue samples were collected for in vitro experiments and biochemical studies. Endothelium dependent relaxation induced by acetylcholine in the aorta and corpus cavernosum tissues were attenuated in the diabetic group, whereas phenylephrine induced contractile responses were reduced. These responses were restored after rosiglitazone and/or insulin treatment, the combination being the most efficient treatment. Malondialdehyde and TNF-alpha levels were increased in diabetic rats while glutathione levels were decreased. All treatments prevented these changes in biochemical parameters, rosiglitazone and insulin combination again being the most efficient treatment. Our results suggested that supplementing diabetic patients receiving insulin treatment with adjunct therapy of rosiglitazone may have some benefit for controlling diabetic complications. (C) 2011 Elsevier B.V. All rights reserved.