Fig. 3. Effects of cadmium (Cd) exposure on glutathione synthesis rates in gill and hepatopancreas (HP) cells of oysters estimated as the rates of cycloheximide-insensitive incorporation of [³H]Gly. Mean values of glutathione synthesis in the cells exposed to different Cd levels (x-axis) for 4 h at 20°C are expressed as % of the respective controls. Vertical bars represent s.e.m. The asterisk denotes values significantly different from the respective control [P<0.01; the dagger denotes a marginally significant difference (P=0.09)]. N=5.