[6,7-3H]Estradiol exchange for estimation of estrogen-receptor complex on nuclear sediment
Abstract
A method based on the translocation of cytoplasmic estrogen-receptor complex to the nuclei in cell-free system was established for the estimation of nuclear estrogen-receptor complex. The homogenates of uteri of rabbits or rats were prepared by using buffers containing a low concentration of estradiol and incubated at 30 degrees for 30 min. The nuclear sediment was then isolated from the homogenates incubated with [6,7-3H]estradiol-17beta in order to fully exchange the unlabeled ligand bound in the nuclear estrogen-receptor complex.
The [6,7-3H] estradiol exchanged may be increased 3-fold compared with control which had not been treated with estradiol prior to the separation of nuclear sediment. The amount of exchange estimated represented the level of estrogen receptor in the target tissues. The binding affinity of estrogen receptor in rat uterus was estimated to be 1.8*10(9) M(-1) (Ka).
Keywords:
The [6,7-3H] estradiol exchanged may be increased 3-fold compared with control which had not been treated with estradiol prior to the separation of nuclear sediment. The amount of exchange estimated represented the level of estrogen receptor in the target tissues. The binding affinity of estrogen receptor in rat uterus was estimated to be 1.8*10(9) M(-1) (Ka).