IN-VITRO DOSE-RESPONSE STUDY OF THE EFFECT OF CADMIUM ON EEL (ANGUILLA-ANGUILLA) GILL NA+ K+-ATPASE ACTIVITIES/

The effect of cadmium exposure was studied in vitro on the ATPase acti vities of gill membrane microsomes from seawater- and freshwater-adapt ed eel (Anguilla anguilla) using a microassay technique. The basal act ivity (Mg2+-ATPase) was decreased by 40 and 25%, respectively, in seaw ater and freshwater preparations for the highest concentrations tested (respectively, 4 and 2 mu M). The Na+/K+-ATPase activity was estimate d either by potassium stimulation or by ouabain inhibition. This enzym e activity was inhibited by cadmium in a dose-dependent manner with a I-50 of 146 +/- 9.3 nM. Neither the technique used to measure the enzy me nor the adaptative environment significantly changed the I-50. The results are compared to results obtained in other groups and to the ef fects of cadmium on metal ion exchanges in fish. (C) 1994 Academic Pre ss, Inc.