Inhibition of T3-receptor binding by Nitrofen.

Lung development is controlled by various hormones, including thyroid hormone. The herbicide 2,4-dichlorophenyl-p-nitrophenyl ether (Nitrofen) induces lung hypoplasia in fetal rats, when administered to the mother during gestation. Nitrofen might be teratogenic by an anti-thyroid activity. The present study shows that Nitrofen decreases the binding of T3 to the alpha 1 and beta 1 form of the thyroid hormone receptor in a non-competitive way. Consequently, rat lung hypoplasia might result from the decreased binding of T3 to its receptor, via exposure to Nitrofen during fetal development.