The Genotoxic Effects Of Pentachlorophenol On Bufo Raddei And The Activity Changes Of GST And LDH

Pentachlorophenol (PCP), as a wide spectrum pesticide has been used widely, has become a major pollutant to the environment. Many studies have reported that the effects of PCP on organisms and the genetic effects in organisms. Yet these results are contradictory and no final conclusion has been reached on the genetic toxicity of PCP. Amphibians have been accepted as the indicator of the environmental pollution and employed to investigate the effects of various pollutants on organisms and the environment. However, few studies have been performed to observe the genetic toxicity effects inflicted on amphibians by PCP, especially the PCP intoxication. Bufo raddei is a widely distributed species in the north of China. The experimental toads were treated by PCP through endermic injection at a dose of 0.0,12.5,25.0 mg/Kg once time (acet is control) and were sacrificed at the end of 3 ,12 and 48 hours after once treatment. The effects of PCP on the micronucleus and nucleus abnormity in the blood cells and DNA damage and enzyme activity of livers and kidneys were observed and detected. Additionally, the high performance liquid chromatography (HPLC) was utilized to determine the quantity of the residual PCP within the livers and kidneys of B. raddei and provide proposals for the early prevention and control of PCP in the water.The results indicated that the ratio of abnormal nuclei after treatment with PCP was higher and significantly different from the control (P<0.01), which increased with the increase in the PCP concentration, and increased initially and then decreased with the protraction of the treatment time. For the female B. raddei, the variation in the ratio of both micronuclei and abnormal nuclei exhibited the same tendency, while the variation of the ratio of micronuclei within the male was indistinguishable. In all, the treatment of PCP exerted significant influences on the ratio of micronuclei and abnormal nuclei in female and male B. raddei and no difference between the female and the male was observed(P>0.05).Besides, the results also showed that PCP significantly induced the DNA damage of the liver cells and had great genetic toxicity on B. raddei. The result showed that the percentage and extent of DNA damage after treatment with PCP were significantly higher compared with control (P<0.01); The percentage of DNA damage of the liver cells in male and female B. raddei increased initially and then decreased with the protraction of the treatment time, so did the extent of DNA damage of the liver cells in female B. raddei. The percentage and extent of DNA damage of liver cells were higher compared with kidney cells.The liver and kidney of B. raddei was also designated to study the effects of PCP on the activity of Glutathione Transferase (GST) and Lactate Dehydrogenase (LDH). The results showed that the GST activity within the liver of the male was apparently induced 3 hours after the intoxication of B. raddei and began to deduce and finally kept stable with the elongation of the treatment time, whilst the GST activity didn't exhibit significant variation throughout the treatment within the treated female B. raddei. Furthermore, both PCP-injected male and female body of B. raddei showed the similar variation in the GST activity, which decreased firstly and then rose with the prolongation of time. However, the variation tendency of the activity of LDH within treated male and female B. raddei was not clearly observed.The experimental findings from the treatment with low concentrations of PCP were that a small quantity of PCP brought serious toxicity to amphibians. All things considered, the application of PCP into the crop fields must be absolutely banned and the successful establishment of the sewage discharge standard can be preceded by comprehensive considerations.