Effects Of Heavy Metal On Metallothionein And Enzymes Activities Of Earthworms

In this paper, earthworms were cultivated in different concentration of soil which were Omg/kg.5mg/kg、50mg/kg、100mg/kg of Cu²⁺、Ag⁺、Cr⁶⁺. After seven days,using DTNB to determinate metallothionein and GSH-Px kit to determinate GSH-Px.Studied the effects of different concentration of Cu²⁺、Ag⁺、Cr⁶⁺ on metallothionein and glutathione peroxidase of earthworms. The results showed that in the same concentration, Cr⁶⁺、Ag⁺ could promote the content of MT,while Cu²⁺ inhibited it.Cr⁶⁺ had better promotion than Ag⁺.When the concentration was 50mg/kg, Cr⁶⁺ had the best promotion,while Ag⁺ was in 5mg/kg. Cr⁶⁺、 Ag⁺ and Cu²⁺ could promote the enzyme activity of GSH-Px. In the same concentration, Cr+ had better promotion than Cu²⁺ and Ag⁺. When the concentration was 50mg/kg, Cr6、Cu²⁺ had the best promotion,while Ag⁺ was in 5mg/kg. Four concentration gradients of cadmium ion were added into soil cultivation to culture earthworms. The activity of three kinds of protective enzymes superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） were determined by spectrophotometry to research effects of different concentrations of cadmium on three kinds of protection enzymes. In this experiment, POD, SOD, CAT produce abnormal activity compared with the control group in earthworm after Cd treatment, which indicate that Cd produced a toxic effect and inhibited Cd on POD and SOD. However, the increase of activity of enzymes performed after 9 days. Furthermore, the inhibition and induction of CAT by Cd was irregular.