KHODABANDEH, Saber*; ESMAILI SARI, Abbas; Univ. of Tarbiat Modarres; Univ. of Tarbiat Modarres: Effects of copper on branchial Na+,K+-ATPase immunoreactivity in Astacus leptodactylus (Crustacea, Decapoda)

Copper is an essential element and acts as a cofactor for a number of key proteins, however, in excess, it is toxic. Na+,K+-ATPase is present in the ion-transporting type branchial filaments (chloride cells) of Astacus leptodactylus. Antibodies to Na+,K+-ATPase have been widely to identify chloride cells in fish and crustacean. Juvenile A. leptodactylus were exposed to waterborne copper (3 �mol l-1) for 10 days and the branchial chloride cells were identified by Na+,K+-ATPase immunocytochemistry. The mean optical density of Na+,K+-ATPase stained chloride cells in branchial filaments epithelium of controls and copper exposure was 0.956�0.024 (N=12) and 0.542�0.019 (N=10), respectively. The number of stained chloride cells decreased from 89% in controls to 53% in copper�exposed Astacus . We observed that copper affected the branchial cells: hemocyte accumulate in vessels and filaments, the epipodite is hypertrophied with a disorganized epithelium and hemolymphatic edema. In conclusion, copper exposure increases levels of necrosis and apoptosis of branchial chloride cells and necrotic and apoptotic cells have much lower Na+,K+-ATPase antigenicity than mature chloride cells.