Effects of acute and subacute exposures to cadmium on the interrenal and thyroid function in rainbow trout, Oncorhynchus mykiss

Juvenile rainbow trout, Oncorhynchus mykiss, were exposed to 0.4, 0.8 and 2.4 mg Cd l(-1) (CdCl2 in water) for 2, 4, 24, and 96 h and to 0.4 and 0.8 mg Cd l(-1) for 1 week to investigate the effects of short term exposures to Cd on the interrenal and thyroid function. Acute (2-4 h) exposure increased both plasma cortisol and T4 levels but had no effect on plasma T3. Following a subacute exposure (1 week), plasma cortisol levels of the exposed fish increased compared with controls, plasma T4 levels decreased and plasma T3 levels remained stable. An increase in plasma glucose and a decrease in liver glycogen was detected in fish exposed for 1 week, no effect on weight gain was found. Short term exposures to sublethal concentrations of Cd induce changes in the endocrine status and carbohydrate metabolism of the fish.