Effect of Nickel on the antioxidant system of <i>Styela clava</i>

Abstract

<i>S. clava</i> were exposed to sublethal concentrations of nickle (0.01, 0.05, 0.1 or 0.2 mg Ni L^-1) for 40 days. Biochemical stress response of <i>S. clava </i> was studied taking into account superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), as well as lipid peroxidation (LPO). Present study confirms the presence of antioxidant enzymatic activity in the tissues of <i>S. clava</i>, reflecting a physiological adaptation to continuous metal exposure in their natural environment. Ni exposure induced a significant SOD, CAT and GPx activity inhibition in ascidians. After several days of exposure, the enzymatic activities recovered to some extent during continuous Ni treatment, that may be a contributing factor for the animals’ self-repair.