Osteolathyrogenic effects on the developing rat foetus.

SKELETAL and aortic changes in foetal rats treated with osteolathyrogenic agents via the maternal system throughout pregnancy or very late in pregnancy have been described by Stamler (1955). Developmental changes in Xenopus larvae (Chih, Witschi, & Ponseti, 1954) and in salamander and toad larvae (Levy, 1955) have also been described. The abnormalities produced in these forms by these agents have apparently been related to a direct effect of the agent on the mucopolysaccharide ground substance. No attempt has been made in a mammal to determine if there are specific time-susceptible periods in embryogenesis when this type of stimulus may induce true teratogenic effects. The present study was devised to determine the effect of a known osteolathyrogenic agent during specific stages of gestation and especially to observe the effect of this agent during the early critical stages of embryogenesis.