RESUMO
To elucidate the ichthyotoxic mechanism of the harmful dinoflagellate Cochlodinium polykrikoides, a bioassay using damselfish was conducted. After exposure to a live-cell suspension of C. polykrikoides, all the fish were died within 90 min. In the presence of catalase and superoxide dismutase (SOD), no significant reduction in the toxicity of C. polykrikoides on the fish was observed. Furthermore, no significant levels of reactive oxygen species (ROS) were detected in five strains of C. polykrikoides isolated in Japan. Our results support the idea that certain toxic substances, rather than ROS, are mainly responsible for the fish-killing activity of C. polykrikoides.
Assuntos
Eucariotos/patogenicidade , Perciformes/microbiologia , Animais , Bioensaio , Eucariotos/citologia , Eucariotos/isolamento & purificação , Eucariotos/metabolismo , Sequestradores de Radicais Livres/metabolismo , Peróxido de Hidrogênio/metabolismo , Espaço Intracelular/metabolismo , Óxido Nítrico/metabolismo , Espécies Reativas de Oxigênio/análise , Espécies Reativas de Oxigênio/metabolismo , Superóxidos/metabolismoRESUMO
In raphydophyte cell suspensions such as those of Chattonella marina, C. ovata and Heterosigma akashiwo, a gradual increase in NO-specific fluorescence intensity was observed, and the increase in the fluorescence intensity of each of these phytoplankters was completely inhibited in the presence of carboxy-PTIO, a specific NO scavenger. However, no such significant changes were observed in the case of other phytoplankter species.
