Meeting Abstract

P1.11  Wednesday, Jan. 4  Cadmium and Calcium Transport in Gill Cells of Ucides cordatus, a Mangrove Crab ZANOTTO, F/P*; ORTEGA, P; CASTRO, J/M; SA, M/G; UNIVERSIDADE PRESBITERIANA MACKENZIE, SAO PAULO; UNIVERSITY OF SAO PAULO, SAO PAULO; UNIVERSIDADE PRESBITERIANA MACKENZIE, SAO PAULO; UNIVERSITY OF SAO PAULO, SAO PAULO fzanotto@mackenzie.br

Cadmium (Cd) is a transition metal, non-essential for animals and can cause many adverse effects such as alteration of other essential ions during cellular transport. Cd transport has not been studied in detail in crustaceans and it seems to interact with calcium (Ca) transport, an essential ion for crustacean molting. Therefore, the present work was undertaken to characterize Cd transport in gill cells of a crab found in contaminated mangrove regions. For that, gill cells were marked with fluo-3 and the change in fluorescence was followed with the addition of Cd alone, Ca alone and Cd + Ca together in the following equimolar concentrations (0.5, 1.0 and 1.5 uM). Results show that Cd enters gill cells and after 5s the fluorescence decreases to baseline values. Cd transport alone causes a change in fluorescence (ΔF x 4s-1) from 600 (0.5 uM) up to 1,600 for Cd at 1.5 uM. The fluorescence change is smaller for anterior compared to posterior gill cells. Addition of Cd+Ca decreases fluorescence change for all concentrations at around 50%, compared to Cd transport without Ca. BAPTA, a selective intracellular Ca chelator was incubated with gill cells at 2 mM and after that Cd transport was measured. Results show that the change in fluorescence for all Cd concentrations varies from 5-10 fluorescence units in the presence of BAPTA. This work shows that Cd enters gill cells, and equilibrates intracellularly within 4-5 seconds. Moreover, intracellular Ca seems to interfere with Cd transport by decreasing Cd influx dramatically through yet unknown mechanisms. Project supported by FAPESP grant 2009/15546-3 and Mackpesquisa.