Abstract
TCDD induced cleft palate (CP) in C57BL6N embryos by altering proliferation and differentiation of palatal medial epithelial cells. These effects correlated with altered expression of the growth factors, TGF-α, EGF, TGF-β1 and TGF-β2, and the EGF receptor. Synergistic interactions between TCDD and retinoic acid (RA) or hydrocortisone (HC) resulted in CP induction at doses too low to induce CP if given alone. Clefts produced by TCDD + RA or TCDD + HC were due to growth inhibition, an outcome differing from that of TCDD alone. TCDD, RA, and HC all had different effects on growth factor expression with the strongest effects on TGF-β, TGF-α, and EGF. In palatal organ culture, concentration-dependent effects on medial epithelial cells occurred in C57BL/6N mouse, F344 rat, and human palates. The responsiveness to TCDD was absent in serum-free cultures, suggesting that an additional factor is required in vitro . The mechanism of TCDD activity appears to involve growth factor expression and may interact with RA and glucocorticoid pathways.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
