Accumulation Of DSP Toxins And P-glycoprotein Expression In Perna Viridis Exposed To Prorocentrum Lima

Diarrhetic shellfish poisoning(DSP) toxins is a common type of shellfish toxins,which are found in the sea area all over the world.DSP toxins can lead to the diarrhetic poisoning of humanity,and more,induce tumor after exposed to DSP toxins. However,the shellfish are not sensitive to the DSP toxicity,which can eat toxin-producing algae and accumulate DSP toxins in tissue.Some special toxin resistance mechanism in the shellfish may be responsible for the insensitivity to DSP toxins.To explore the roles of p-glycoprotein(p-gp) in resistant mechanism of shellfish to DSP toxins,Prorocentrum lima was used as resources of DSP toxins, Phaceodactylum tricornutum as foods,the accumulation and cleaning action of DSP toxins in Perna viridis were studied,and p-gp gene expression induced by DSP toxins were detected.The grazing rates of Perna viridis were shown to decrease significantly in a dose-respones relationship,suggesting the negative impact of DSP toxins on the shellfish.The distribution of DSP toxins varied in different tissues.The amount of DSP toxins in gillwas was higher than those in others,accounting for the total toxin content of 64.2%.After exposed to P.lima,the level of DSP toxins in the gill of Perna viridis increased significantly in a dose-dependent relationship with time,and achieved the highest at the 3rd day.However,the toxin levels in Perna viridis decreased significantly after withdrawal of Prorocentrum lima.The p-gp expression increased obviously in a dose-dependent relation,and achieved the highest at the 3rd day,then decreased.These results suggested that Perna viridis had some resistant ability to DSP toxins,and the p-gp gene expression might have an important role in the resistant mechanism.