Inhibition of Ca2+ uptake in freshwater carp, Cyprinus carpio, during short-term exposure to aluminum.

In carp exposed to pH 5.2 in fresh water, the Ca2+ influx from the water is reduced by 31% when compared to fish in water of neutral pH. At pH 5.2, the Ca2+ influx but not Na+ uptake is decreased by aluminum (Al). Al reduces Ca2+ influx dose-dependently: a maximum 55% reduction was observed after 1-2 h exposure to 200 micrograms.1(-1) (7.4 microM) Al. Branchial Ca2+ efflux is less sensitive to Al and affected only by exposure for more than 1 h to high Al concentrations. Na+ influx is not affected by concentrations Al up to 400 micrograms.1(-1). Na+ efflux, similarly to Ca2+ efflux, increased when fish were exposed for more than 1 h to 400 micrograms.1(-1) Al.