STRESS PROTEINS HSP60 AND HSP70 IN 3 SPECIES OF AMPHIPODS EXPOSED TO CADMIUM, DIAZINON, DIELDRIN AND FLUORANTHENE

To investigate the use of stress proteins hsp60 and hsp70 as sublethal biomarkers for contaminant exposure in sediments, two infaunal (Ampel isca abdita, estuarine; Rhepoxynius abronius, marine) and one epifauna l (Hyalella azteca, freshwater) amphipod species were exposed far 24 h to solutions of the heavy metal cadmium, the pesticides diazinon and dieldrin, and the polycyclic aromatic hydrocarbon fluoranthene. All th ree species are routinely used in standard sediment toxicity tests. An alysis of hsp60 and hsp70 was performed using western blotting techniq ues with subsequent comparative quantification by densitometry. Result s demonstrated compound and species-specific induction of stress prote in synthesis. Whereas one member of the hps70 protein family showed th e most sensitive response to xenobiotic compounds in H. azteca, severa l members of the hsp60 protein family were the main proteins induced i n A. abdita and R. abronius. Sensitivity of the detected stress protei n response was highest in H. azteca with significant effects at concen trations 110-, 50-, >1,000-, and >1-fold lower than LC50 values for ca dmium, diazinon, dieldrin, and fluoranthene, respectively. The corresp onding values were >5 (cadmium), 0.7 (diazinon), >1 (dieldrin), and 2. 9 (fluoranthene) for A. abdita, and >2 (cadmium), 3.1 (diazinon), >100 (dieldrin), and >2.9 (fluoranthene) for R. abronius.