铜离子对草履虫慢性毒性实验研究

STUDY ON CHRONIC TOXICITY OF COPPER(Ⅱ) IONS ON PARAMECIUM.

本文的目的在于观察铜离子对草履虫的繁殖毒性、有丝分裂相细胞比率、生长抑制和刺丝泡不发射率的作用。结果表明：Ｃｕ２＋对草履虫产生繁殖毒性，有丝分裂指数降低，生长抑制的阈浓度为０．０１９５ｍｇ／Ｌ（Ｐ＜０．０１）。随Ｃｕ２＋浓度的逐渐增加，相对繁殖率逐渐降低，刺丝泡的不发射率逐渐增高，存在明显的浓度－反应关系（Ｐ＜０．０１）。但是，分裂相细胞比率的下降和体长的阶梯性抑制均无明显浓度依赖关系（Ｐ＞０．０５）。我们的结果表明长时间接触浓度大于０．０１９５ｍｇ／Ｌ的Ｃｕ２＋对草履虫的ＤＮＡ有损伤作用，干扰蛋白质、核酸等生物大分子的合成，从而影响草履虫的细胞分裂、繁殖和生长。本研究提出繁殖实验是监测铜离子对水生物慢性毒性敏感的方法。

The present study was preformed to observe the effects of Reproductive toxicity,Mitotic cell ratio,Growth inhibition and Notrichocyst rate of copper(Ⅱ) ions on paramecium.The results showed that the threshold concentrationof Cu^2+ exposed for 48 hours,inducing the reproductive toxicity,mitoticindex reducing and growth inhibition of paramecium was 00195mg/L(P<001),that of inducing notrichocyst rate increase was 00391mg/L(P<001).Relative reproductive rate decreased and the notrichocyst rate increased as rising concentration of Cu^2+.They existed significant concentrationresponse relationship(P<001);But no definite concentrationdependent mannar was evident(P>005),both decreasing of mitotic cell ratio and stepped inhibition of body length.Our results also indicated that the concentration equalling or more then 00195mg/L of copper(Ⅱ) ions exposed for long time induced DNA damaged of paramecium,disturbed synthesis of nucleic acid and proteins.thus cell division,reproduction and growth of paramecium were influenced,The study suggested that the reproduction test is a more sensitive method in mornitoring of chronic toxicity of copper(Ⅱ) ions on aquatic creatur.