Joint action of benzoic hydrazide and beta-aminopropionitrile on Xenopus embryo development.

Binary mixtures of the osteolathyrogens benzoic hydrazide and beta-aminopropionitrile were tested to determine the joint action for these chemicals, by evaluating induction of malformation and osteolathyrism in developing frog embryos. Exposures, starting with late-blastula stage embryos, were for 96-h with solution renewal every 24-h. Five treatments were examined, each chemical alone (i.e., 1:0 and 0:1 solutions) and three mixtures (i.e., 3:1, 1:1, and 1:3). Following exposure, embryos were evaluated grossly and the incidences of all types of malformations and osteolathyrogenic lesions were determined. Toxic unit analysis and isobole diagrams indicated these chemicals were concentration additive in inducing malformations and osteolathyrism. Therefore, benzoic hydrazide and beta-aminopropionitrile induce osteolathyrism, in Xenopus embryos, in a similar manner.