Interactive dysmorphogenic effects of all-trans-retinol and ethanol on cultured whole rat embryos during organogenesis
✍ Scribed by Chen, Hao; Yang, Hsueh-Ying L.; Namkung, Moses J.; Juchau, Mont R.
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 769 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0040-3709
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✦ Synopsis
Whole rat conceptuses (10.5 gestational days) were explanted into a culture medium containing all-trans-retinol (t-retinol, vitamin A,), ethanol, or combinations of the two alcohols at various concentrations, and were cultured at 37°C for 24 hr. Parameters emphasized in morphological analyses were bronchial arch development, closure of neural tube, axial rotation, and development of otic vesicles and of optic cup. Additions of t-retinol alone to the culture medium resulted in significant decreases in viability at concentrations of 7.0 KM and above. A primary target site affected by t-retinol was the second bronchial arch. With initial culture medium concentrations of 3.5 pM, 28% of embryos exhibited an underdeveloped second bronchial arch, and the effect was concentration dependent. Incubations with t-retinol alone also caused failure of closure of neural tubes, underdevelopment/absence of otic and optic vesicles, and failure of normal axial rotation, but these effects were statistically significant only at the higher concentrations (1 0.5-14.0 FM). Incubations of conceptuses with ethanol alone resulted in statistically significant decreases in viability and increases of incidence of embryonic abnormalities at 50 mM but not at 10or 20-mM concentrations. The embryotoxicity of ethanol appeared less site-specific than that of t-retinol. However, ethanol-elicited developmental abnormalities included underdevelopment of the first and second bronchial arches, abnormally open neural tubes, abnormally small or absent otic and optic vesicles, and incomplete axial rotation in common with effects elicited by t-retinol. In general, embryos incubated with combinations of t-retinol and ethanol showed lower survival rates and higher incidences of developmental abnormalities when compared to the calculated values expected for simple additive effects; i.e., interactive effects were most frequently greater than additive and probably synergistic but not antagonistic. To