Teratogenic effects of L-asparaginase in rat embryos in vitro

The teratogenic potential of L-asparaginase has been assayed in New cultures of explanted rat embryos. Embryos treated on day 9.5 with 1.5 IU L-asparaginase/ml of culture medium exhibited growth and development retardation together with malformations of the brain (exencephalia), eyes (anophthalmia or rudimentary sulcus opticus), face (characteristic appearance with anomalous frontolateral protrusions) and trunk (myeloschisis and turning absence). Neural ectoderm alterations were observed upon histological examination (anomalous fusions between the confronted neural folds as a consequence of the lack of turning and thickening) together with strong vascular dilatations at the cephalic level. Treatment on day 10.5 only caused minor differences in growth and protein content with respect to the control embryos. The possible teratogenic mechanism of this enzyme is discussed.