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(W/EH063) Adenylate energy charge and histopathology as biomarkers of zinc effects on the bivalve Ruditapes decussatus L. Picado, Ana1, Mendonça, Elsa1, Castro, Luísa2, Peres, Isabel2, 1 2 ABSTRACT- Marine invertebrates, especially molluscs, accumulate trace metals and thus their body concentrations can reach high metal levels (Zorba et al., 1992). Zinc has been the objective of several studies because their concentrations are increasing significantly in the sea. Adenylate energy charge (AEC) is directly related to the cellular concentrations of the three adenylates nucleotides ATP, ADP and AMP. In invertebrates, AEC displays a wide range of values according to the importance of the internal stress or to the variations in the external environment of the organisms (natural or anthropogenic). For the understanding involved in the metal accumulation it is essential to assess metal distribution in the tissues. Histopathological biomonitoring studies shown that histopathology is a valuable discipline for determining effects on cells and tissues (Yevich & Yevich, 1994). In this work studies on zinc accumulation and the evaluation of effects at AEC and histological alterations were done with the bivalve Ruditapes decussatus submitted to experimental pollution at sublethal concentrations. Our results show that AEC is modified in organisms submitted to experimental pollution. Results of zinc contamination in adults of clam Ruditapes decussatus show that AEC values drops significantly after one month exposure to sublethal concentrations. Through histochemical observation zinc was detected in the organs: gill, hepatopancreas and kidney, but also in blood cells. AEC and histophatology are presented as biomarkers of exposure. Key words: biomarkers, AEC, histopathology, zinc |
