In vitro testing for developmental toxicity using the Hydra attenuata assay.

The developmental hazard of six chemicals was tested in vitro in the Hydra attenuata assay which is based upon the differential toxicity between the adults and a regenerating stage known as an artificial "embryo". The toxicity of DMSO, ethyl alcohol, lindane and paracetamol was similar for both adults and embryos. On the other hand, sodium valproate and isoniazid was, respectively, seven and 100 times more toxic for embryos than adults, thus indicating that these pharmaceuticals might pose developmental hazards to mammalian development. The differential toxicities seen in the Hydra assay reflect analogous data on laboratory animals.