重金属对凡纳滨对虾血细胞吞噬活力的影响

为研究不同重金属离子对虾类血细胞的免疫抑制作用,凡纳滨对虾(Ltiopenaeus vannamei)血细胞在离体状态下暴露于重金属离子(Cd^{^(2+})、Hg²⁺、Cu²⁺和Zn²⁺),浓度分别设置为10^-3～10^-9 M,在胁迫6h后应用流式细胞术测定血细胞的吞噬活力。结果显示,与对照组相比,浓度为10^-3～10^-5 M的Cd²⁺和Hg²⁺、10^-3～10^-4 M的Cu²⁺、10^-3 M的Zn²⁺均显著抑制了对虾血细胞的吞噬活力;当浓度为10^-3 M时,Cd²⁺、Hg²⁺、Cu²⁺和Zn²⁺组的吞噬活力抑制率分别为79.6%,82.6%、68.1%和58.7%。这些结果表明,一定浓度的重金属离子对虾类血细胞吞噬活力具有免疫抑制作用,免疫抑制毒性强度依次为:Hg²⁺>Cd²⁺>Cu²⁺>Zn²⁺,免疫毒性临界浓度分别为:Cd²⁺和Hg²⁺10^-5 M、Cu²⁺10^-4 M、Zn²⁺10^-3 M。

Effects of heavy metals on phagocytic activity of Litopenaeus vannamei haemocyte

To explore the immunotoxic effects of several heavy metals on shrimp haemocytes,haemocytes from the white shrimp Litopenaeus vannamei were exposed to heavy metals (Cd^2+,Hg^2+,Cu^2+ and Zn^2+) in vitro.The doses of the heavy metals were 10^-3 ~10^-9 M.Phagocytic activity of haemocytes was analyzed after 6 h exposure using flow cytometry.Results showed that phagocytic activity was significantly depressed by 10^-3 ~10^-5 M Cd^2+ and Hg^2+,10^-3 ~10^-4 M Cu^2+ and 10^-4 M Zn^2+,compared to the control group without heavy metals.The inhibition rate on phagocytic activity were 79.6%,82.6%,68.1% and 58.7% respectively while haemocytes exposed to Cd^2+,Hg^2+,Cu^2+ and Zn^2+ at 10^-3 M.These results indicate that heavy metals are immunotoxic for phagocytic activity of shrimp haemocytes when the dose reached a certain level,and the immunotoxicity ranked in the following order:Hg^2+ >Cd^2+ >Cu^2+ >Zn^2+.The The toxic critical concentrations of Cd^2+,Hg^2+,Cu^2+ and Zn^2+ were 10^-5 M,10^-5 M,10^-4 M and 10^-3 M.