Document Type : Original Research Paper
University of Sousse, Tunisia
This study investigated the cytochemical responses in Hediste diversicolor exposed to the environmental concentrations of cadmium (1µM Cd), copper (1µM Cu) and to their equimolar mixture for 48h. Lysosomal membrane stability (LMS), neutral lipids (NL) level, lipofuscin (LF) content and Ca2+-ATPase activity were determined as early subcellular biomarkers of toxicity. The biomarker battery pointed out a high cytoxicity on the polychaete treated with metals. Excessive induction of neutral lipids and lipofuscin accumulations were observed in polychaete treated with copper than cadmium. In addition, the highest level of neutral lipids and lipofuscin was noted in mixture treated group [Cu+Cd]. The increase of neutral lipids and lipofuscin accumulations were negatively correlated with the lysosomal membrane stability and Ca2+-ATPase activity alterations. Our study also demonstrated that the cytochemical biomarkers responses were very important to identify the cellular toxic effects of metals and promising biological tools in the assessment of biological effects of pollutants in natural marine environment.