重金属对罗氏沼虾血细胞活性和酯酶活力的影响

为探讨不同重金属对罗氏沼虾(Macrobrachium rosenbergii)血细胞的细胞毒性,取罗氏沼虾血淋巴,离体状态下分别暴露于不同浓度(10~(-9)~10~(-3) mol/L)的Cd~(2+)、Hg~(2+)、Cu~(2+)和Zn~(2+)环境中6 h,设置不添加重金属的对照组,应用流式细胞术测定细胞活性和胞内非特异性酯酶活力。结果显示,10~(-9)~10~(-6) mol/L的Cd~(2+)对细胞活性和酯酶活力均没有显著影响,Cd~(2+)浓度达到10~(-5) mol/L时,酯酶活力受到了显著的抑制,Cd~(2+)浓度达到10~(-4)和10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-6) mol/L的Hg~(2+)对细胞活性和酯酶活力均没有显著影响,Hg~(2+)浓度为10~(-5)~10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-5) mol/L的Cu~(2+)对细胞活性和酯酶活力均没有显著影响,Cu~(2+)浓度为10~(-4)~10~(-3) mol/L时,细胞活性和酯酶活力均显著下降;10~(-9)~10~(-5) mol/L的Zn~(2+)对细胞活性和酯酶活力均没有显著影响,Zn~(2+)浓度为10~(-4) mol/L时,酯酶活力显著下降,Zn~(2+)浓度为10~(-3) mol/L时,细胞活性和酯酶活力均显著下降。Cd~(2+)、Hg~(2+)、Cu~(2+)和Zn~(2+)对细胞活性的毒性临界浓度分别为10~(-4) mol/L、10~(-5) mol/L、10~(-4) mol/L和10~(-3) mol/L,毒性强度由高到低依次为Hg~(2+)、Cd~(2+)、Cu~(2+)、Zn~(2+)。Cd、Hg、Cu和Zn这4种重金属对罗氏沼虾血细胞活性和酯酶活力均具有明显的剂量效应;酯酶活力对重金属胁迫较细胞活性更为敏感,可作为虾类细胞毒理学研究的重要指标。

Effects of heavy metals on cell viability and esterase activity of hemocytes from the freshwater prawn, Macrobrachium rosenbergii

To explore the toxic effects of several heavy metals on hemocytes from Macrobrachium rosenbergii,we evaluated the cell viability (CV) and esterase activity (EA) of the M.rosenbergii hemocytes after in vitro exposure to 10-9-10-3 mol/L heavy metals (Cd2+,Hg2+,Cu2+,and Zn2+,compared with a control group without exposure to heavy metals) for 6 h by flow cytometry.The results showed no significant effects of 10-9-10-6 mol/L Cd2+ on CV and EA.10-5 mol/L Cd2+ significantly inhibited EA.Both CV and EA significantly decreased after exposure to 10-4 mol/L and 10-3 mol/L Cd2+.There were no significant effects of 10-9-10-6 mol/L Hg2+ on CV and EA,whereas 10-4 mol/L and 10-3 mol/L Hg2+ significantly decreased CV and EA.Concentrations of 10-9-10-5 mol/L Cu2+ had no significant effects on CV and EA;however,10 4-10-3 mol/L Cu2+ significantly decreased CV and EA.Although 10-9-10-5 mol/L Zn2+ had no significant effects on CV and EA,10-4 mol/L Zn2+ significantly decreased EA,whereas 10-3 mol/L Zn2+ significantly decreased CV and EA.The toxic critical concentrations of Cd2+,Hg2+,Cu2+,and Zn2+ were 10-4 mol/L,10 5 mol/L,10-4 mol/L,and 10-3 mol/L,respectively.The toxicity of these four heavy metals on M.rosenbergii hemocytes ranked in the following order:Hg2+ > Cd2+ > Cu2+ ＞ Zn2+.The toxicity of heavy metals on M.rosenbergii hemocytes was dose-dependent.EA is more sensitive to heavy metal stress,and could be used as an indicator for toxicology studies.