Calcium influences radio-cobalt uptake by the common carp, **Cyprinus carpio**
Faculty of Sciences. Biology
Studies in environmental science / Sri Venkateswara University. Department of Education [Tirupati] - London
, p. 321-328
University of Antwerp
The effect of different calcium concentrations on the uptake of cobalt through the gills of the common carp, Cyprinus carpio, was studied in chemically defined freshwater. Fish were acclimated for 16 days to a set of different calcium concentrations, while cobalt uptake experiments were conducted over a 3-hour period at the same range of calcium concentrations. A clear decrease in cobalt influx with increasing calcium concentrations in the water of exposure was observed. The effect of the calcium concentration in the water of acclimation is significant, but of minor importance. Increasing the free cobalt ion activity in the water increases the cobalt influx, while calcium influx is inhibited. High calcium levels in the water reduce the blocking of calcium influx by cobalt. Since uptake kinetics of both cobalt and calcium show similar results for influx in body, gills and blood, and both elements inhibit each others uptake, a competitive interaction at the apical translocation system of the gill epithelium is suggested.