Cadmium Transport in Epithelial Cells of a Crab: comparison between Gills and Hepatopancreas

Cadmium (Cd) is a non‐essential metal for crustaceans and is responsible for alterations in ion transport in a number of animals. Cd transport has not been studied in detail in crustaceans. Therefore, the present work was undertaken to characterize Cd transport in gill and hepatopancreatic cells of a crab, Ucides cordatus , found in contaminated mangrove regions. Cells were marked with a fluorescent probe (Fluo‐3) and the change in fluorescence was followed with the addition of Cd (0, 1.0 and 1.5 ìM), ATP (1.5 ìM) and different inhibitors. Results show that Cd enters gill cells and the fluorescence decreases to baseline values within few seconds. Cd transport for posterior gills is double that for anterior gills in terms of fluorescence change (1,600 against 800 ÄF × 5s −1 × 22.10 4 cells, respectively). ATP added together with Cd at 1.5 ìM causes a decrease in fluorescence, suggesting an efflux of intracellular Cd. For hepatopancreas, different cell types display different Cd uptake. Embryonic (E) and resorptive cells (R) showed the highest Cd uptake compared to the other cells, and the uptake was lower than that seen for gill cells (1,600 against 1,000 ÄF × 5s −1 × 22.10 4 cells, respectively). Results show that Cd enters gill and hepatopancreatic cells, and equilibrates intracellularly within 4–5 seconds. Moreover, Cd influx is followed by a rapid cell sequestration and a decrease of intracellular Cd in these crab cells.