Browsing by Author "Devrim, Erdinc"

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Effects of High-Cholesterol Diet and Antioxidant Vitamins Combination on Oxidant/Antioxidant Status in Heart, Kidney, Liver and Testis Tissues From Rats
(Wiley, 2007) Devrim, Erdinc; Ozbek, Hanefi; Durak, Ilker
Possible effects of a high-cholesterol diet on the oxidant/antioxidant status in various tissues from rats and the effects of the combination of vitamins C and E on these parameters and on hypercholesterolemia were investigated. Twenty-four Sprague-Dawley type rats were randomly divided into three groups. The control group (group 1) was fed on a rat pellet diet. The study groups (groups 2 and 3) were fed on a high-cholesterol diet for 3 months. Rats in group 3 were supplemented with vitamins C (100 mg/kg intraperitoneally ) and E (60 mg/kg intramuscularly ) three times a week throughout the study. At the end of the study period, all animals were sacrificed and their heart, kidney, liver and testis surgically removed to measure oxidant and antioxidant parameters. Blood samples were also obtained from the animals. We observed that serum total cholesterol levels significantly increased in the study groups after the study period. The increase in the blood cholesterol level in group 3 was, however, significantly lower than that in group 2. As to the oxidant-antioxidant parameters, there were different results among the tissues. In conclusion, our results suggest that high serum cholesterol level does not lead to oxidation reactions in the early phase of hypercholesterolemia, and antioxidant vitamins supplementation increases antioxidant potential values of the tissues and decreases the blood total cholesterol level in the cholesterol-supplemented animals.
High-Cholesterol Diet Increases Xanthine Oxidase and Decreases Nitric Oxide Synthase Activities in Erythrocytes From Rats
(Pergamon-elsevier Science Ltd, 2008) Devrim, Erdinc; Erguder, Imge B.; Ozbek, Hanefi; Durak, Iiker
The aim of this study was to investigate the effects of a high-cholesterol diet on oxidant/antioxidant status and nitric oxide synthase (NOS) activity in erythrocytes from rats. Sixteen Sprague-Dawley-type albino male rats were used in the study. The rats were randomly divided into 2 groups: the control group (group 1) was fed a standard rat diet, and the treated group (group 2) was fed a high-cholesterol diet (4% cholesterol, 1% cholic acid, and 0.5% thiouracil) in addition to standard pellet rat diet for 3 months. At the end of the study period, blood samples were obtained from the rats under ether anesthesia. Oxidant (malondialdehyde level, sensitivity to oxidation value, and xanthine oxidase [XO] activity) and antioxidant parameters (antioxidant potential value, superoxide dismutase, catalase, and glutathione peroxidase activities) were studied in erythrocyte preparations. Activities of erythrocyte NOS and arginase enzymes and serum total cholesterol levels were also measured. We observed that serum total cholesterol levels, erythrocyte XO activities, and sensitivity to oxidation values significantly increased in group 2 (cholesterol fed) compared with the control group (group 1). Erythrocyte NOS activities were also found to decrease in group 2. In conclusion, our results suggest that cholesterol feeding causes an increase in XO activity and a decrease in NOS activity in the erythrocytes from rats. The increase in XO activity may render the erythrocyte membranes sensitive to oxidant stress, and the decrease in NOS activity in the erythrocytes may increase cardiovascular disease risk via reduced endothelial relaxation. (c) 2008 Elsevier Inc. All rights reserved.