| dc.description.abstract | The purpose of this study was twofold. One aspect was to continue validation of the Frog Embryo Teratogenesis Assay: Xenopus (FETAX). The second aspect was to develop a developmental toxicity species comparison test of early life stages between the African clawed frog (Xenopus laevis) and the fathead minnow (Pimephales promelas). FETAX is a 96-hr whole embryo bioassay designed to evaluate pure compounds or mixtures. Fetotoxicity, teratogenicity, and effect on growth are the parameters explored. Validation �enables FETAX to be useful as a rapid, routine test of developmental toxicity. In this study validation was performed by testing five compounds (ascorbic acid, sodium selenate, coumarin, serotonin, and 13-cis retinoic acid) .and comparing the results with data from mammalian lit~ratu!e. The results of this portion of the study�were consistent with mammalian data and support the use of FETAX for the screening of developmental toxicants. The second aspect of this study, a species comparison test, was performed in order to compare Pimephales promelas and Xenopus laevis. This study of species sensitivity differences in developmental toxicity was performed using sodium acetate, c~ffeine, and 5-fluorouracil. An exposure time of 120 hrs allowed for similar embryological events for each species to occur during the test. The relative amount of uptake of chemical by each species was determined by liquid scintillation spectrometry of whole fish and frog residue. | |
