Effects of exposure to cadmium on some endocrine parameters in tilapia, Oreochromis niloticus.

The cadmium impact on interrenal and thyroid functions was assessed in tilapia, Oreochromis niloticus. Fish were exposed to 25 mg L(-1) of CdCl(2) during 24, 48, and 96 h. Exposure to 24 and 48 h induced a significant increase in plasma cortisol levels, whereas at 96 h no differences were found. A significant and sustained decrease in plasma T3 concentrations, and an over time increase in plasma glucose, was also found in exposed fish. The results of the current study show that acute exposures to sublethal cadmium concentrations induce changes in endocrine status and carbohydrate metabolism in O. niloticus.