Browsing by Author "Emre, Mustafa"

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Deterioration of Bone Quality by Streptozotocin (stz)-Induced Type 2 Diabetes Mellitus in Rats
(Humana Press inc, 2011) Erdal, Nurten; Gurgul, Serkan; Kavak, Servet; Yildiz, Altan; Emre, Mustafa
Patients with diabetes mellitus (DM) have various skeletal disorders and bone quality can be impaired in DM leading to fractures. Wistar albino male rats (270-300 g; n=16) were assigned randomly to nondiabetic and diabetic rats (single dose intravenous injection of 45 mg/kg streptozotocin). All rats in each group were perpetuated for 8 weeks, and blood glucose levels as well as body weights were measured once weekly. Biomechanical measurements were performed at the mid-diaphysis of the left femur with tensile test. Extrinsic and intrinsic properties were measured or calculated. Bone mineral density (BMD) was also evaluated and measured by dual-energy X-ray absorptiometry. Cross-sectional area of the femoral shaft was evaluated by computerized tomography. Blood glucose levels in diabetic rats were significantly increased compared to that of the nondiabetic rats, while the body and femur weights were decreased (P<0.05). In respect to the BMD, cross-sectional area and femur length, there were no statistically significant differences between the nondiabetic and diabetic rats (P>0.05). The maximum load, ultimate stress, and toughness endpoints in diabetic rats were significantly decreased compared to that of the nondiabetics (P<0.05). There were no statistically significant differences between the nondiabetic and diabetic rats with regard to the displacement and stiffness (P>0.05). Femurs of diabetic rats had less absorbed energy than that in nondiabetics (P<0.05). Ultimate strain was lower in diabetic rats than that in nondiabetics, while the elastic modulus was higher (P>0.05). The bone quality of rats is decreased by streptozotocin-induced type 2 diabetes mellitus.
The Effects of High-Rate Frequency Modulation Treatment on Malondialdehyde in Diabetic Polineuropaty
(Blackwell Publishing, 2006) Kavak, Tuyana; Kavak, Servet; Emre, Mustafa; Tulgar, Metin; Dulger, Haluk; Cankaya, Soner
Effects of Insuline on Oxidative Stress and Free Fatty Acid Level in Left Ventricular Muscles of Diabetic Rats
(Asian Journal of Chemistry, 2009) Kavak, Servet; Ayaz, Lokman; Emre, Mustafa; Bozkurt, Abdi
Studies were carried out to examine and compare the effects of streptozotocin-diabetes on 3-nitrotyrosine (3-NT), Malondialdhyde (MDA) and lipid profiles related parameters in the heart from male rats. Effects of insulin (INS) treatment were also evaluated. The diabetic state severely compromised the 3-NT, MDA and lipid profiles defense mechanism in the left ventricular muscle tissue and the effects were more pronounced in the male rats. Wistar albino male rats were randomly divided into an untreated control group (C), a diabetic group (D) that was treated with a single intraperitoneal injection of streptozotocin (STZ) (45 mg kg(-1)), D + INS group which were treated with INS one times a day by injection subcutaneous, respectively. Lipid profiles, HbA1c and blood glucose levels in the circulation and MDA and 3-NT levels in left ventricular muscle were measured. Treatment of diabetic rats with INS resulted in a time-dependent decrease in blood glucose. It is found that the lipid profile and HbA1c levels in D + INS group reached the untreated control group rat values at the end of the treatment period. It is found that the lipid profile and HbA1c levels in D + INS group reached the C rat values at the end of the treatment period. In group D, 3-NT and MDA levels were found to be increased when compared with C and D + INS groups. In the D + INS group, MDA levels were found to be decreased when compared with untreated control group. This study shows a direct correlation between hyperglycemia and the production of MDA and nitrotyrosine, a marker of oxidative stress, in diabetic rat left ventricular muscle.
The Effects of Mesenchymal Stem Cells Applied During the Subacute Period in Peripheral Neuropathy
(Cukurova Univ, Fac Medicine, 2024) Kiroglu, Olcay; Maytalman, Erkan; Alizade, Ares; Emre, Mustafa; Zorludemir, Suzan; Aksu, Fazilet
Purpose: The study aims to investigate the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) administered subacute period to neuropathic mice on allodynia and nerve-muscle tissue functions during 24 weeks. Materials and Methods: Peripheral neuropathy was induced by partial sciatic nerve ligation. Experiments were conducted in Control, Sham, Neuropathic, BM-MSC, and Neuropathic+BM-MSC groups. Allodynia was measured by cold plate test at the 2nd, nd , 6th, th , and 24th th weeks. Electrophysiological and histopathological examinations were performed on isolated nerve-muscle tissues at the end of the 24th th week. Results: Allodynia threshold increased in the Neuropathic+BM-MSC group (7.76 +/- 0.33 sec) from the 6 th week and continued to increase along 24 weeks compared to the Neuropathic group (4.36 +/- 0.21 sec). Action potential (137.9 +/- 7.85 mV) and depolarization (0.74 +/- 0.01 msec) values of the Neuropathic+BM-MSC group exhibited partial improvement compared to the Neuropathic group (121.5 +/- 3.03 mV and 0.81 +/- 0.02 msec, respectively) at the 24th th week. Muscle tissue's resting membrane potential values increased in the Neuropathic+BM-MSC group compared to the Neuropathic group (-73.4 +/- 0.2 and-87.7 +/- 0.2 mV, respectively). Histopathological examination of nerve tissue revealed loss of myelinated axons and significant fibrosis in the endoneurium in the Neuropathic group while Schwann cell proliferation and preservation of myelinated axons were observed in the Neuropathic+BMMSC group. Muscle fiber atrophy, compensatory hypertrophic fibers, and increased central nuclei were seen in the Neuropathic group, while small atrophic muscle fiber groups were identified in the Neuropathic+BM-MSC group. Conclusion: BM-MSC application in the subacute period is found to reduce allodynia and provide functional recovery in nerve-muscle tissue in experimental peripheral neuropathy.
Positive Inotropic Effect of Rosiglitazone in Papillary Muscles in Control and Diabetic Rats
(Asian Journal of Chemistry, 2009) Kavak, Servet; Emre, Mustafa; Bozkurt, Abdi; Demir, Halit
Peroxisome proliferator-activated receptor gamma activators or rosiglitazone (RSG) used as insulin sensitizers in the treatment of diabetes. The aim of this study is the effects of RSG on papillary muscle positive inotropic were studied in left ventricular papillary muscles from both control rats and rats diabetes. In this study, we used four groups: (1) untreated control (C) (2) rosiglitazone-treated control (C + RSG), (3) diabetes (D) and (4) rosiglitazone-treated diabetes groups (D + RSG). Diabetes was induced by a single intraperitoneal injection of streptozotocin (STZ) for 8 weeks STZ-treatment (STZ, 45 mg/kg). Papillary muscle from spontaneously diabetic hearts exhibited a depressed conraction force (CF), prolonged contraction time (CT) and half relaxation time (1/2 RT) and reduced contraction and relaxation velocities (+- dp/dt) (p < 0.05). It is found that the lipid profile and glycohemoglobin levels (HbA1c) levels in D + RSG group as it increase the C rats value at the end of the treatment period (p < 0.05). D + RSG and C + RSG groups exhibited a increased CF, shortened CT and 1/2 RT and increased dp/dt (p < 0.05). Treatment of rats with RSG also markedly decreased the insulin resistance of the hearts. Present data suggest that the beneficial effects of RSG treatment on the mechanical activities of the diabetic rat papillary appear to be due to the restoration of the diminished SR Ca2+ release triggering, partially, related to the restoration of the hyperglycemia.
Repetitive 50 Hz Pulsed Electromagnetic Field Ameliorates the Diabetes-Induced Impairments in the Relaxation Response of Rat Thoracic Aorta Rings
(Taylor & Francis Ltd, 2009) Kavak, Servet; Emre, Mustafa; Meral, Ismail; Unlugenc, Hakki; Pelit, Aykut; Demirkazik, Ayse
Purpose: To evaluate the characteristic features of mechanical responses and the membrane potential changes induced by repetitive pulsed electromagnetic field (PEMF, 50Hz, 5 mT) in thoracic aorta rings obtained from streptozotocin-induced diabetic and healthy control rats to determine if PEMF could ameliorate problems associated with diabetes. Methods: Sixty male Wistar rats weighing 250-290g were randomly divided into two experimental groups, each containing 30 animals. Streptozotocin was given via tail vein to produce diabetes mellitus (DM) in the first group rats. The second group rats were treated only with % 0.9 saline and considered as non-DM group. Both groups were also divided into two subgroups as DM+PEMF, DM+sham, PEMF and sham, each containing 15 animals. Although the DM+PEMF and PEMF groups were treated, the DM+sham and sham groups were not treated with PEMF. The PEMF treatment occurred four times daily for 30min at 15-min intervals repeated daily for 30 days. Thoracic aorta rings from both DM and non-DM rats exposed to PEMF were evaluated for contraction and relaxation responses and membrane potential changes in the presence or absence of chemical agents that were selected to test various modes of action. Results: Relaxation response of thoracic aorta rings was significantly reduced in DM than non-DM group. PEMF treatment significantly increased the relaxation response of the diabetic rings to acetylcholine, and reduced the concentration response to phenylephrine. Resting membrane potential was significantly higher in DM than in non-DM group. Inhibitors of nitric oxide (NO), both nitro-L-arginine (L-NO-ARG) and L-NO-ARG+indometacin combination, produced a significant transient hyperpolarisation in all groups. Inhibitors of potassium channel activity, charybdotoxin or apamine, produced a membrane depolarisation. However, PEMF did not induce any significant effect on the membrane potential in DM group. Conclusions: Diabetes reduced the relaxation response of thoracic aorta rings. It also affected the membrane potentials of the rings. Treatment with PEMF ameliorated the diabetes-induced impairments in the relaxation response of these rings.