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MECHANISMS OF TCDD-INDUCTION OF CLEFT PALATE: INSIGHTS FROM IN VIVO AND IN VITRO APPROACHES
Citation:
Abbott, B., J. Diliberto, AND L. Birnbaum. MECHANISMS OF TCDD-INDUCTION OF CLEFT PALATE: INSIGHTS FROM IN VIVO AND IN VITRO APPROACHES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/J-92/442 (NTIS PB93141414).
Description:
TCDD induced cleft palate (CP) in C57BL6N embryos by altering proliferation and differentiation of palatal medial epithelial cells. hese effects correlated with altered expression of the growth factors, TGF-a,EGF. TGF-B1 and TGF-B2, and the EGF receptor. ynergistic interactions between TCDD and retinoic acid (RA) or hydrocortisone (HC) resulted in CP induction at doses too low to induce CP if given alone. lefts produced by TCDD + RA or TCDD + NC were due to growth inhibition, an outcome differing from that of TCDD alone. CDD, and NC all had different effects on growth factor expression. xposure to NC + TCDD produced effects on TGF-B1 expression which were NC-like. A + TCDD reduced TGF-B1 levels, a response opposite to that seen for either RA or TCDD. he mechanism of TCDD activity appears to involve growth factor expression and may act through RA and glucocorticoid pathways.