LED Laboratory, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
J Environ Sci (China). 2010;22(7):975-81. doi: 10.1016/s1001-0742(09)60207-2.
Time-dependent Zn and Cd accumulation and metallothionein like protein (MTLP) induction in the digestive glands of mussels, Perna virdis, were measured under different exposure conditions. The initial uptake rate at start of chase (rho0) and mean residence time (tau) were calculated to determine the physiological response of organisms and their potential detoxification mechanisms. It was found that in digestive glands, Zn had obviously higher rho0 and shorter mean residence time than Cd, indicating that these two metals had different accumulation dynamics even though they were very close in the periodic element table. MTLP levels in digestive glands varied from 0.51 to 1.05 microg/g ww (wet weight). The MTLP level increased continuously when mussels were exposed to low and middle levels of Zn and Cd media, and reached maximal levels at day 4, then decreased when they were exposed to high level Zn and Cd solutions. With regard to the fraction of Zn and Cd accumulated in the digestive glands, the ratios of soluble metal to total metal decreased continuously after exposure in low and middle levels of Zn and Cd media, and decreased continuously in the first 4 days and then to level off when mussels were exposed to media with high concentration of Zn and Cd. Results suggested that both MTLP induction and metal insolubilization were detoxification processes in digestive glands of mussels.
在不同的暴露条件下，测量了贻贝消化腺中锌和镉的时间依赖性积累以及金属硫蛋白样蛋白 (MTLP) 的诱导。通过计算初始摄取率（rho0）和平均停留时间（tau），来确定生物体的生理反应及其潜在的解毒机制。结果发现，在消化腺中，锌的 rho0 明显高于镉，平均停留时间较短，这表明这两种金属即使在元素周期表中非常接近，其积累动态也不同。消化腺中的 MTLP 水平在 0.51 到 1.05 微克/克（湿重）之间变化。当贻贝暴露于低中和高水平的锌和镉介质中时，MTLP 水平持续增加，并在第 4 天达到最高水平，然后在暴露于高浓度锌和镉溶液时下降。至于在消化腺中积累的锌和镉的分数，在低中和高水平的锌和镉介质中暴露后，可溶性金属与总金属的比例连续下降，在暴露的前 4 天持续下降，然后趋于平稳。结果表明，MTLP 诱导和金属不溶性都是贻贝消化腺的解毒过程。
