Toxic effects and depuration after the dietary lead(II) exposure on the bioaccumulation and hematological parameters in starry flounder (Platichthys stellatus)

Platichthys stellatus (mean length 20 ± 2 cm, mean weight 160.15 ± 15 g) were exposed to the different levels of dietary lead(II) at the concentrations of 0, 30, 60, 120, 240 mg/kg for 4 weeks. Depuration was conducted for 2 weeks after exposure. The lead exposure over 60 mg Pb/kg induced the significant bioaccumulation in tissues of P. stellatus (5–30 μg/g tissue), except for brain and muscle where the exposure to 240 mg Pb/kg caused the bioaccumulation (2–4 μg/g tissue). The hematological parameters such as red blood cell (RBC) counts, hematocrit (Ht) value and hemoglobin (Hb) concentration were substantially decreased over 60 mg Pb/kg, and lasted even after the depuration period. For plasma components, calcium and magnesium levels in plasma were generally decreased over 60 mg Pb/kg, and glucose level was also mainly increased over 60 mg Pb/kg. Total protein was significantly decreased over 120 mg Pb/kg after 4 weeks exposure. Glucose and total protein showed the restoration after the depuration period in groups of fish exposed previously to over 60 and 120 mg Pb/kg, respectively. However, other parameters that changed during the exposure over 60 mg Pb/kg did not recovered. For enzymatic components in plasma, glutamic oxalate transminase (GOT), glutamic pyruvate transminase (GPT) and alkaline phosphatase (ALP) were significantly increased over 120 mg Pb/kg, and there was only restoration observed after the depuration for ALP over 120 mg Pb/kg.