Determination of Oxidative Stress Responses Induced by the Combination of 4 Different Rare Earth Elements in Dreissena polymorpha; [Determinacija odgovorov na oksidativni stres, ki ga povzroča kombinacija 4 različnih redkih zemljinskih elementov v Dreissena polymorpha]

Rare Earth Elements (REE), whose usage areas are increasing day by day, are increasing in the amount of mixing with the environment, causing changes in antioxidant enzyme activities by causing oxidative stress in living organisms. In this study, it was aimed to examine the oxidative stress responses induced by the mixture of 4 different REEs (terbium, gadolinium, Lanthanum, Praseodymium) in Dreissena polymorpha. For this purpose, sublethal concentration values were determined by literature review. Experimental application was carried out within 24 and 96 hours. In the analyzes performed to determine biomarker responses, samples taken from living organisms were weighed and homogenization processes were performed for the analysis of samples taken from the experimental groups, including the control group. After homogenization, samples were centrifuged at 4.000 rpm for 15 minutes. Supernatants were kept at -86 °C until measurements were made. Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities, and glutathione (GSH) and thiobarbituric acid reactive substances (TBARS) levels were determined using ELISA kits. Statistical analyses were performed using SPSS. One-way ANOVA (Duncan’s multiple range test; p < 0.05) was used for comparison of measured parameters among groups. As a result of the application, a decrease in CAT activity and GSH level and an increase in TBARS levels were observed after 96 hours compared to the control group, while no statistically significant difference was detected in SOD and GPx activities.