Binding of [³H] monohydroxytamoxifen in ovarian carcinoma

Summary. A monoclonal antibody (D‐547) against human breast cancer oestrogen receptor was used to demonstrate that the oestrogen receptor in ovarian epithelial carcinomata binds [³H]monohydroxytamoxifen. This binding was observed in sedimentation velocity analyses of both cytosol and nuclear compartments. Binding of [³H]monohydroxytamoxifen to the antibody‐recognized moiety could be inhibited by diethylstilboestrol or oestradiol, but not by androgen, progestin or corticoid, indicating oestrogen specificity for the binding site. The sedimentation coefficient of the antibody‐recognized [³H]monohydroxytamoxifen binding moiety was similar to that when 16α‐[¹²⁵I]iodo‐oestradiol was used as the ligand.