K. Jesseneller et Jf. Crivello, CHANGES IN METALLOTHIONEIN MESSENGER-RNA AND PROTEIN AFTER SUBLETHAL EXPOSURE TO ARSENITE AND CADMIUM CHLORIDE IN JUVENILE WINTER FLOUNDER, Environmental toxicology and chemistry, 17(5), 1998, pp. 891-896
Juvenile winter flounder (Pleuronectes americanus) from a Long Island
Sound site within the Niantic River region contain elevated levels of
liver As and Cd. Previous work in mammals suggests that a reduced spec
ies of As. NaAs3-, is as potent a metallothionein (MT) inducer as CdCl
2. We investigated whether this is also the case in winter flounder by
subcutaneously exposing juveniles to a sublethal range of NaAs3+ (0,
0.38. 0.75, and 1.5 mu mol/g fish) or CdCl2 (0, 0.045, 0.09. and 0.18
mu mol/g fish). Of the two, CdCl2 was the more potent MT inducer, with
an 8-fold lower molar equivalent causing a 3-fold higher response. Bo
th metals rapidly induced MT protein within 24 h of exposure, but only
the highest dose of CdCl2 elicited a significant increase in MT mRNA.
The magnitude of the MT protein response to CdCl2 (7.25-fold) demonst
rates that elevated liver As and Cd do not narrow the MT response wind
ow in juvenile flounder from the Niantic River region. These fish have
relatively low liver MT protein levels (46 mu g/g) and will be a usef
ul reference population for future metal impact studies within Long Is
land Sound.