Modelling chronic toxicokinetics and toxicodynamics of copper in mussels considering ionoregulatory homeostasis and oxidative stress

Chronic toxicity of copper (Cu) at sublethal levels is associated with ionoregulatory disturbance and oxidative stress. These factors were considered in a toxicokinetic-toxicodynamic model the present study. The was evaluated by activity Na+/K+-ATPase enzyme (NKA), while stress presented lipid peroxidation (LPO) glutathione-S-transferase (GST) activity. NKA related to binding Cu2+ Na + NKA. LPO GST linked simulated concentration unbound Cu. calibrated using previously reported data empirical generated when zebra mussels exposed clearly demonstrated that Cu might inhibit reducing number functional pump sites limited Cu-bound turnover rate. An ordinary differential equation used describe relationship between LPO/GST Although this method could not explain fluctuations these biomarkers during experiment, measurements within confidence interval estimations. Model simulation consistently shows non-significant differences two exposure levels, similar observation.