The effect of estrogen on cadmium distribution in rainbow trout (Oncorhynchus mykiss)

The effects of injections of 17β-estradiol (E2) and Cd, on the distribution of Cd and the induction of metallothionein (MT) mRNA and vitellogenin mRNA was investigated. Bone and liver were the main organs accumulating Cd. However, E2 redirected the metal accumulation from the bone and liver to the gill, gut and muscle upon exposure to E2. Cd did not induce the hepatic MT mRNA levels in animals treated with E2. The VTG mRNA levels were also reduced following co-injection of E2 and Cd. However, the kidney responded to Cd exposure by upregulating MT mRNA even in the presence of E2 treatment. In the liver the reduced MT mRNA induction led to a redistribution of CD from MT to non-MT proteins. The toxicological significance of these alterations in Cd handling remains to be determined.