The embryotoxic and osteolathyrogenic effects of semicarbazide.

The osteolathyrogenic agent semicarbazide was assayed for its toxicity and teratogenicity using early embryos of the frog Xenopus laevis. The 96-h LC50 is 1504.20 mg/l while the 96-h EC50 is 76.28 mg/l. Embryo length is altered prior to the onset of other effects indicated by a reduction in stage of development. The major malformation is associated with the notochord where the notochordal sheath is reduced owing to the disruption in the maturation and/or deposition of the connective tissue fibers.