Cytotoxic activity of the neurotoxin anatoxin-a on fish leukocytes in vitro and in vivo studies.

摘要

The aim of this study was to investigate the potential cytotoxic effects of different concentrations (0.01, 0.025, 0.05, 0.1 and 1 micro g/ml medium) of pure anatoxin-a on carp immune cells (in vitro study). Furthermore, changes in the cell immune functions isolated from 10 carp exposed by immersion to anatoxin-a (25 micro g/l) for 5 days have been examined. Cytotoxicity of the toxin to leukocytes was determined by measuring intracellular adenosine triphosphate and glutathione concentrations. Lymphocyte proliferation was determined by measurement of bromodeoxyuridine incorporation during DNA synthesis. The phagocytes were assayed for intracellular production of reactive oxygen species. The in vitro results showed that pure toxin induced adverse effects on immune cells only after application of the higher concentrations (0.05, 0.1 and 1 micro g/ml). Phagocytes exposed to anatoxin-a exhibited a significant (P<0.05) reduction in glutathione concentration. The lymphocyte proliferation was decreased by the toxin, and B cells were more sensitive than T cells. The present study showed for the first time that anatoxin-a administered to fish by immersion, had suppressive effects on lymphocyte proliferation and the antioxidant potential of phagocytes.