IMMUNOLOCALIZATION OF NA+, K+-ATPASE ENZYME AND GILL CHLORIDE CELLS IN FRIES OF PERSIAN STURGEON, ACIPENSER PERSICUS

Persian sturgeon, Acipenser persicus is a valuable species in the Caspian Sea ecosystem. For gill chloride cells localization, fish specimens 2-3g were adapted to experimental conditions for 7 days. Gill histology was observed through light microscopy using Hematoxylin-Fushin staining. Immunolocalization of gill Na+, K+-ATPase was observed through fluorescent microscopy using mouse monoclonal antibody (IgGa5) rinsed against (Na+, K+-ATPase a-subunit. Chloride cells dimensions was observed using Image Tools software.Gill chloride cells that have high densityof Na+, K+-ATPase, were found on gill arch, gill septum, filament and lamellae. No chloride cells were observed on spiracular or opercular gills epithelium. Chloride cells were spherical to egg-shaped and showed immunefluorescent activity on their baso-Iateral sides. Results showed that in each square millimeter of gill epithelia, 289 chloride cells existed and the maximum number of these cells was found on filament, lamellae, base of the lamellae and on the inter-lamellar space. We also found that the number of these cells is significantly different in all branchial states. Persian sturgeon fry weighing 2-3g have gill chloride cells where Na+, K+-ATPase gene and their activity occurred. Because of their cellular transporters (like Na+, K+-ATPase), these cells were the main sites of the ionic and osmotic regulation between the fish and the environment.