³H-Corticosterone Incorporation in CBA and Transferred A/Jax Embryos in CBA Mothers

Abstract

The ³H-corticosterone incorporation in mouse embryos of resistant and sensitive mouse strains was studied using blastocyst transfer technique. There was no greater incorporation of the labelled corticosteroid in the sensitive A/Jax embryos transferred as blastocysts compared to native CBA embryos in the CBA mothers. These results do not support the hypothesis that a difference in concentration of teratogen at the receptor site should be the reason for a strain difference in cortisone-induced cleft palate in the A/Jax and CBA strains. Studies with various labelled corticosteroids given at various stages of embryonic development and measured by different methods are discussed in order to find an explanation for the strain difference in drug-induced malformations.