红纺锤水蚤(Acartia erythraea)对Cu^(2+)和Ag^+的吸收

Waterborne copper and silver interaction on a marine copepod, Acartia erythraea

通过对桡足类动物红纺锤水蚤(Acartiaerythraea)分别在Cu2+、Ag+、Cu2++Ag+混合溶液中的暴露实验,测定了其对Cu2+、Ag+的吸收速率常数、排出速率常数,并对Cu2+和Ag+在动物体内的分布状况进行了分析.结果表明,在单金属暴露的条件下,红纺锤水蚤对Cu2+、Ag+的吸收速度分别为1.09×104L·g-·1d-1、3.31×104L·g-·1d-1,排出速率常数分别为0.096d-1、0.1056d-1.而在Cu2++Ag+的混合暴露体系中,红纺锤水蚤对Cu2+、Ag+的吸收速率分别下降到9.17×103L·g-·1d-1、2.87×104L·g-1-d-1,Cu2+和Ag+的排出速度常数则分别降到0.084d-1和0.1008d-1.动态模型的模拟结果表明,Cu2+和Ag+存在一定程度的拮抗作用.与暴露在单金属溶液中的红纺锤水蚤相比较,在暴露于Cu2+、Ag+混合体系中动物体内的非极性部分所占的比重明显增加,说明其在食物链中对于上一营养级的生物有效性将明显增加.

Marine copepods, Acartia erythraea, were exposed to waterborne copper, silver, and copper and silver mixture respectively in a series experiment during which the metal contents in exoskeleton, polar and nonpolar parts in animal cells were measured and the uptake rate, efflux rate constant for Cu^2 ＋ and Ag^＋ were calculated. The metal uptake rate, efflux rate constants were 1.09 10^4 L·g^-1·d^-1, 0.096 d^-1 for Cu^2＋, 3.31 × 10^4 L·g^-1·d^-1, 0. 1056 d^-1 for Ag^＋ respectively when copepods were exposed to single Cu^2 ＋ or Ag^＋ solution.Their counterparts in Cu^2＋＋Ag^＋ mixture exposure experiments decreased to 9.17 × 10^3 L·g^-1· d^-1, 0. 084 d^-1 for Cu^2 ＋ , 2.87 × 10^4 L·g^-1· d^-1, 0. 1008 d^-1 for Ag^＋ respectively. The measuring and kinetics modeling results suggested the antagonism interaction between waterborne Cu^2＋ and Ag^＋ exits in marine copepods. The different distribution of Cu^2＋ and Ag^＋ among exoskeleton, polar and nonpolar parts in copepods revealed that the metal bioavailability in copepods exposed to metal mixture increased in some degree compared to their counterparts exposed to single metal solution.