Effect of low-level copper and pentachlorophenol exposure on various early life stages of xenopus laevis

摘要

An envaluation of the effects of low-level copper and pentachlorophenol exposure on various early life stages of the South African clawed frog, Xenopus laevis, was performed using stage-specific and long-term continuous exposures. Stage-specific exposure experiments were conducted such that separate subsets of embryos and larvae from the same clutch were exposed to two toxicants, copper and pentachlorophenol, from 0 d to 4 d (standard Frog Embryo Teratogenesis Assay - Xenopus (FETAX), 4 d to 8 d, 8 d to 12 d, and 1 2 d to 16 d. Results from two spearate concentratioin-response experiments indicated that sensitivity to either toxicant increased in each successive time peeriod. Longer-term exposure studies conducted for 60 to 75 days indicatedthat copper, but not pentachlorophenol induced reduction deficiency malformations of the hind limb at concentrations as low as 0.05 mg/L. Pentachlorophenol concentrations as low as 0.5 mu g/L inhibited tail resorption. However, copper did not adversely affect the process of tail resorption. These results indicated that studie evaluating longer-term development processes are important in ecological hazard evaluation.