The nuclear 3,5,3'-triiodothyronine receptor in human leukaemic cell lines

Abstract
The 3,5,3'-triiodothyronine (T3) receptor has been studied in a series of continuously growing human leukaemic cell lines. High concentrations of receptor were found in the erythroblastoid cell line K-562. T3 was bound to the nuclei of these cells with an association constant of 3.4 × 109 m−1, and capacity 104 fmol/100 μg DNA, or 8700 molecules/nucleus. This capacity is comparable to that of rat liver or growth hormone producing cells (GH cells) in culture, and suggests that the K-562 cell line could be a useful model for the study of T3 action on erythroid differentiation.