CONTROL OF METALLOTHIONEIN EXPRESSION BY HORMONES AND STRESSORS IN CULTURED FISH CELL-LINES

In-vitro studies with established cell lines from a marine flatfish (turbot) and an anadromous fish (rainbow trout) were used to study hormonal effects on metallothionein synthesis. Only the turbot cell line responded to glucocorticoid and progesterone treatments, with a 1.5-2-fold induction of MT levels. Neither cell line displayed a positive response to oestradiol, phorbol ester or bacterial endotoxin. A practical implication of these findings in use of fish-metallothionein levels for heavy-metal pollution monitoring is that sexually mature animals must not be used and levels less than 3-fold higher than reference sites, which may be due to hormonal effects, must be disregarded.