EFFECTS OF CADMIUM ON PLASMA-CATECHOLAMINES IN THE AMERICAN EEL, ANGUILLA-ROSTRATA

The impact of up to 16 weeks' exposure to environmentally realistic low and high concentrations of cadmium (75 and 150-mu-gl/l, respectively) on the plasma catecholamines was studied in the American eel, Anguilla rostrata. After 8 and 16 weeks of exposure to 150-mu-g/l of Cd, the baseline concentrations of dopamine (DA), norepinephrine (NE) and epinephrine (E) were below control levels. The changes were less consistent in the eels exposed to the lower dose. Exposure to the high Cd concentration impaired the initial response of plasma DA to mild short-term stress (1 min exposure to CO2 bubbles), but did not have a clear impact on the stress response of NE and E. It is concluded that long-term exposure to 150-mu-g/l of Cd interferes directly or indirectly with the release of CAs from the adrenomedullary equivalent of the American eel.