Effect of okadaic acid on carpet shell clam (Ruditapes decussatus) haemocytes by in vitro exposure and harmful algal bloom simulation assays
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Okadaic acid (OA), produced by dinoflagellates during harmful algal blooms (HAB), belongs to the Diarrheic Shellfish Poisoning toxins that cause gastrointestinal symptoms in humans after consumption. In the present work, Ruditapes decussatus haemocytes were selected to evaluate the effect of OA on cell viability, enzymatic status and immune capacity through the measure by flow cytometry of apoptosis–cell death, non-specific esterase activity and phagocytosis. In order to compare different exposure conditions, two experiments were developed: in vitro exposure to OA and HAB simulation by feeding clams with the OA producer, Prorocentrum lima. Apoptosis was not OA dose-dependent and cell death increased in both assays. Phagocytosis of latex beads and esterase activity decreased in haemocytes incubated with OA. In contrast, esterases increased during the feeding with P. lima. Our results showed that OA and the simulated HAB caused damages on haemocyte functions and viability.
KeywordsApoptosis Flow cytometry Haemocyte Harmful algal bloom Okadaic acid
This work was funded by the project 07MMA013103PR. Consellería de Innovación e Industria, INCITE (Xunta de Galicia). Fernanda Flórez Barrós and Juan Fernández Tajes were supported by “Lucas Labrada” and “Angeles Alvariño” programs, respectively, both from Consellería de Innovación e Industria, Xunta de Galicia). We also would like to thank Dr. Gerardo Martínez for his help in OA determination.
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