Showing papers by "Göksel Şener published in 2016"

Regular exercise alleviates renovascular hypertension-induced cardiac/endothelial dysfunction and oxidative injury in rats.

Abstract: The importance of physical activity in the management of renovascular diseases is well-known, but lacks evidence of underlying mechanisms. The purpose of the study was to elucidate the protective/therapeutic effects of regular exercise on experimental renovascular hypertension (RVH)-induced oxidative stress and cardiac dysfunction. Wistar albino rats underwent a RVH surgery (2K1C, Goldblatt). Three weeks later half of the rats started swimming exercise for 9 weeks (n = 15), while the sedentary RVH group (n = 15) had no exercise during that period. Sham-operated control rats (n = 10), had the similar surgical procedures but the left renal artery was left unclipped. Body weights were monitored, and blood pressures were measured weekly using tail-cuff. Echocardiographic evaluation was performed on the 3(rd) week and on the 12(th) week of the experiment before the rats were decapitated. Heart and thoracic aorta were removed and serum was collected, while aortic samples were put in a 10% formaldehyde solution for immunochemistry. Cardiac tissue samples obtained from each animal were used for the determination of tissue myeloperoxidase (MPO) and catalase (CAT) activities, malondialdehyde (MDA), and glutathione (GSH) levels. In the sedentary RVH group, aortic contractile response (contraction/relaxation in isolated organ bath), left ventricular diastolic and systolic dimensions, and immunohistochemical staining of aortic inducible nitric oxide synthase (iNOS) were increased, while ejection fraction and aortic endothelial nitric oxide synthase (eNOS) staining were decreased. RVH in the sedentary rats resulted in increased pro-inflammatory cytokines (TNF-α, IL-2, IL-6), lipid peroxidation (malondialdehyde) and neutrophil infiltration (myeloperoxidase activity) along with reductions in antioxidant glutathione and catalase levels in the cardiac tissue. Exercise after RVH increased the immunohistochemical staining of aortic eNOS, decreased iNOS staining and reversed the alterations in echocardiographic and oxidative parameters. Regular exercise commenced after RVH surgery alleviated renovascular hypertension-induced oxidative injury, by modulating oxidant-antioxidant balance via the involvement of the endothelial NO system.

Estrogen receptor agonists alleviate cardiac and renal oxidative injury in rats with renovascular hypertension.

Abstract: 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 ERβ agonist diarylpropiolnitrile (1 mg/kg/day) or ERα 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 ERβ 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 ERβ-mediated protective effect was observed in the kidney. Our data suggest that activation of ERβ 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.

Aqueous garlic extract protects against sepsis-induced toxicity in pulmonary and ileal tissues

Abstract: Objective: Based on the potent antioxidant effects of aqueous garlic extract (AGE), the present study was designed to characterize the potential of AGE to modify blood coagulation parameters as well as and pulmonary and ileal injury in septic rats. Sepsis was induced using the caecal ligation and perforation (CLP) method. Methods: Twenty-four hours after sepsisinduction, rats were decapitated and trunk blood was collected for the measurement of platelet counts, fibrinogen, prothrombin time, activated partial thromboplastin time and D-dimer levels. Then, pulmonary and ileal tissue samples were immediately obtained and stored at – 70oC for malondialdehyde (MDA), glutathione, myeloperoxidase (MPO) and superoxide dismutase (SOD) activity assays. Results: Sepsis was associated with a decrease in platelet count and fibrinogen and an increase in APTT and INR. It also caused a significant decrease in GSH levels and SOD activity in both pulmonary and ileal tissue samples. On the other hand, AGE treatment in rats with CLP caused significantly augmented the level of these antioxidants. As a result of CLP induction increased MPO activity and MDA levels and decreased thromboplastic activity were reversed with AGE treatment. Conclusion: AGE treatment, through its antioxidant effects, protects against oxidative pulmonary and ileal injury and normalizes the impaired coagulation in sepsis.