The toxic and accumulative effects of short-term exposure to cadmium in rainbow trout (Oncorhynchus mykiss)
Melgar, M.J.; Perez, M.; Garcia, M.A.; Alonso, J.; Miguez, B.
Veterinary and Human Toxicology 39(2): 79-83
1997
ISSN/ISBN: 0145-6296 PMID: 9080631 Document Number: 469729
Groups of 20 juvenile trout were exposed for 3 week periods to different subacute oral doses of Cl2Cd (0.01, 0.025 or 0.05 micro g Cd/ml). Cadmium toxicity and accumulation were studied in kidney, liver, gills, muscle and brain weekly using atomic absorption spectroscopy with graphite furnace. After 21 days exposure, cadmium concentrations increased significantly in all tissues studied except muscle and brain. Cadmium storage was greater in the kidney than in the liver, which was greater than in the gills. Early in the dosing period, cadmium accumulation was linearly dose dependent. At the highest dose (0.05 micro g Cd/ml) accumulation increased rapidly during the second week of exposure until equilibrium was reached. However, the liver did not accumulate cadmium selectively, and it is suggested that liver is able to eliminate cadmium, perhaps through metallothionein formation. Cadmium levels in gills of dosed fish were higher than controls and showed signs of equilibrium after the first week. According to organ weight/body weight ratios, liver and kidney ratios increased dose dependently, but gills and brain did not have significant differences. Organ growth is affected as cadmium accumulates but it is suggested that it is not dangerous to eat these trout as cadmium was not detected in muscle.