The embryolethality and teratogenicity of acrolein in cultured rat embryos

Abstract
Acrolein, a three‐carbon unsaturated aldehyde, is teratogenic to rats in vivo following intraamniotic administration but has been reported not to be teratogenic in vitro in the rat whole embryo culture system. In this study the effects of acroleion on rat embryos cultured in the standard medium consisting of rat serum were assessed over a narrow‐concentration range. Additionally, a comparison was done of the effects of culture in a serum medium vs. a serum‐free medium. In the serum medium acrolein caused 100% embryolethality at 140 μM and was found to be teratogenic in the concentration range of 80–120 μM. In the serum‐free medium acrolein was 100% embryolethal at 20 μM and was teratogenic in the range of 5–15 μM. The EC50 for malformations in the serum medium was 137 μM, whereas that for embryolethality was 115 μM; the EC50s for malformations and embryolethality in the serum‐free medium were 2.8 μM and 8.3 μM, respectively. Malformations were observed in the brain, facial area, and heart in addition to blebs and twisted or kinked bodies. Decreases in yolk sac diameter, crown–rump length, head length, number of somites, morphological score, and protein content were observed within the teratogenic ranges in each type of medium. Thus acrolein is teratogenic and embryolethal in vitro as well as in vivo. Dissociation between embryolethality and teratogenicity was seen in the serum‐free medium. The slope of the acrolein log concentration‐response curve in the serum‐free medium was twice that in the serum medium, indicating that acrolein may have a different mechanism of action in this medium.