Lethality, teratogenicity and growth inhibition of heptanol in Xenopus assayed by a modified frog embryo teratogenesis assay-Xenopus (FETAX) procedure

The frog embryo teratogenesis assay-Xenopus (FETAX), a powerful test for the presence of developmental toxicants, has been modified mainly by performing an in vitro fertilization and increasing the exposure time to 112 h. The modified assay (modFETAX) that presents several advantages over the original FETAX methodology has been validated by the use of ZnSO4, a standard teratogen for FETAX. The modFETAX has been applied to evaluate the 1-heptanol effects on mortality, malformation and growth inhibition. The results indicate that heptanol causes a significant growth inhibition of Xenopus tadpoles and that LC50 and TC50 at 120 h are, respectively, 1.49 and 0.37 mM; the resulting teratogenic index (TI50) of 4.03 suggests that heptanol is a strong teratogen.