Relationship between metallothionein and metal contents in red-blooded andwhite-blooded Antarctic teleosts

Metal bioaccumulation and metallothionein were investigated in different or gans of the red-blooded teleost, Trematomus bernacchii and the haemoglobinl ess Chionodraco hamatus. Specimens of the two Antarctic fish were sampled f rom Terra Nova Bay (Ross Sea), and their levels of Cd, Cu and Zn in homogen ates and in soluble fractions of liver, muscle, gills, heart and plasma wer e determined. Dosages of metallothioneins (MTs) or MT-like proteins were as sayed by the silver saturation method in soluble fractions of the same orga ns. In both T. bernacchii and C. hamatus the highest MT contents were found in liver. Hepatic MT and Cd, Cu and Zn concentrations correlated positivel y in T. bernacchii, whereas in C. hamatus hepatic MT showed a positive corr elation only with Cd. Positive correlations were also found between Cd and MT in gills of the two species. A metal-binding protein containing a high p ercentage of cysteine from C. hamatus was purified and compared with the MT from T. bernacchii and mammals.