Hg^(2+)、Pb^(2+)对克氏螯虾触角神经放电联合作用研究

A Study of Joint Action of Hg^(2+), Pb^(2+) on Discharges of Antennule-inner Ramus Nerve of Crayfish (Cambarus clarkii)

本实验应用多通道电生理记录方法，观察Hg2+和Pb2+对克氏螫虾第一触角内侧枝神经放电的联合作用。结果显示，从表示其放电频率（Fn／F1）与作用时间关系的直线回归方程的b值可知，水中Hh2+的浓工只有其渔业水体最高允许量（0．0001mg／L）的1／2，水中若还含有浓度≥0．0125mg／L的Pb2+，或水中Pb2+的浓度只有其渔业水体最高允许量（0．1mg／L）的1／2，水中若还含有浓度≥0．0000125mg／L的Hg2+，这两种金属离子联合对克氏鳌虾触角神经放电的抑制作用就会超过单一Hg2+或Pb2+最高允许量的毒性水平（b值分别＜－0．08129±0．0357和＜－0．07731±0．00451），而且在一定浓度范围内，随着Pb2+或Hg2+浓度的增大，其毒笥作用随之增大。表明Hg2+和Ph2+的毒性具有相互增强的联合作用。提示，在渔业水体水质评估中对此似应予以必要的重视。

The joint action of Hg2+, Pb2+ on the discharges of antennule - inner ramus nerve of crayfish (Cambarus clarkii) has been studied by means of multi-channal recording of electrophysiological method. When the concentration of Hg2+ in water is only 1/2 of the limited concentration (0. 001mg/L) in fishery water but also there are 0.0125mg/L Pb2+ in the water,the joint inhibition of the two heavy metallic ions on the discharges is much stronger than the limited concentration of Hg2+. The b value which indicates the relationship between frequency of the discharges (Fn/F1) and action time is < - 0. 08129 ± 0. 00357. Moreover, in certain concentration range, the higher the concentration of Pb2+ is, the stronger the inhibition is. When the concentration of Pb2+ in water is only 1/2 of the limited concentration (0. 1mg/L) Pb2+ in fishery water but also there are 0. 0000125mg/L Hg2+ in the water, the joint inhibition of the two heavy metallic ions on the discharges is much stronger than the limited concentration of Pb2+. The b value which indicates the relation between frequency of the discharge (Fn/F1) and action time is < - 0. 07731 ± 0.00451. Furthermore, in certain concentration range, the higher the concentration of Hg2+ is, the stronger the inhibition is. The results suggest that there are possibly enhanced effects of the toxicity of Hg2+ and Pb2+ each other. It should be devoted much attention to this in the evaluation of water quality.