Accumulation of lead and zinc and effects on activities of catalase and GPT in the clam Ruditapes philippinarum A

Acute toxicities of Pb and Zn to clam (if. philippinarum) were determined by a semistatic bioassay. The 96 h LC50 values were 14.28 mg/L for Pb, and 16.40 mg/L for Zn. Exposure of R. philippinarum to various concentration of lead and zinc for a period of 4 days showed that different organs have different capacities for accumulating metals, with high levels in the gill, followed by soft body, and lower amounts in the cavity fluid. Accumulation tests showed that R. philippinarum is a strong accumulator of Pb and weaker accumulator of Zn. The effect of lead on activities of Catalase and GPT were studied in soft body of R. philippinarum. The result showed that the activities of CAT in soft body decreased at all exposure groups, the activities of CAT were negatively correlated with exposure concentration of lead, the special inhibition effect was observed in exposure group of Zn, the CAT activities significantly decreased at lower Zn concentration, then increased slowly with the Zn concentration, finally, decreased to the lowest. The activities of GPT in soft body were significantly increased at high exposure concentrations.