Investigation of chronic iris oxidative stress in rats effect on parameters

Oxidative stress plays a role in the pathogenesis of many metabolic diseases, especially neurological and cardiovascular diseases. Oxidative stress can cause obesity by stimulating the accumulation of white adipose tissue and also by altering food consumption. It has been shown by both invitro and invivo studies that oxidative stress causes proliferation, differentiation and growth in mature fat cells in preadipocyte cells. To reduce the increasing prevalence of obesity, a wide range of strategies are recommended, including regular physical activity, ad libitum food intake, meal replacements, micronutrient supplementation, and dietary intake of fruits and vegetables. Weight loss with exercise has been documented to reduce oxidation markers, increase antioxidant defense, and reduce pathological risk factors associated with obesity. However, the effects of irisin, known as the exercise hormone, on the oxidative stress parameters that occur with obesity are not fully understood. It is known that the acute effect of irisin plays very important roles in energy expenditure and oxidative metabolism. In this thesis, it was aimed to determine the possible role of irisin hormone applied to obese female and male rats on oxidative stress parameters. Two main groups of Sprague-Dawley female and male rats were used in the study. Both groups were divided into 4 subgroups including control, irisin, obese and obese+irisin (n=10) groups. An obesity model was created by feeding adult female rats in the obese and obese+irisin groups with a 60% kcal high-fat diet for an average of 14 weeks and male rats for 22 weeks. Then, subcutaneous irisin (100 ng/kg/day) was released by mini-osmotic pump to all female and male rats in irisin and obese+irisin groups for 28 days. At the end of the study, all female and male animals were decapitated and blood samples were taken and TAS, TOS, GSH and SOD levels were examined by ELISA (Enzyme-Linked Immunosorbent Assay) method. With this thesis study, the positive effect of irisin hormone on the total antioxidant and total oxidant system in the direction of antioxidants shows that irisin hormone has an important role behind the positive contribution that occurs during exercise. Likewise, the therapeutic role of irisin application on decreasing antioxidants (GSH, SOD) in obese groups also reveals that irisin hormone may mediate the positive effects of exercise.