The estrogen-induced vitellogenin synthesis in chicken liver after estrogen withdrawal or antiestrogen treatment.

(1) The induction of vitellogenin synthesis in chicken liver by an estrogen implant as well as the decline of vitellogenin synthesis and nuclear receptor concentration after withdrawal of the implant were studied. For the detection of vitellogenin the SAC immunoprecipitation technique was used. The nuclear receptor decreases very rapidly and somewhat earlier than the capacity of the liver to synthesize vitellogenin. (2) The inhibition by antiestrogens of the estrogen-induced vitellogenin synthesis as well as of the accumulation of the estrogen-receptor complex in the nucleus was investigated. Tamoxifen as well as the recently described 1,1,2,2-tetramethyl-1,2-bis(4'-hydroxyphenyl)ethane were found to be true antiestrogens in the chicken liver, i.e. they inhibit estrogen-induced vitellogenin synthesis but themselves cause no induction.