Effect of colchicine on estrogen action. II. Translocation of 17 beta-estradiol cytosol receptor complex into the nucleus.

Colchicine has previously been shown in our laboratory to inhibit 17 beta-estradiol stimulation of uterine water uptake in the immature rat measured 6 h after administration of the agents. We sought to determine whether this effect was mediated through colchicine action on translocation of estradiol receptor complex into the uterine cell nucleus. The time course of estradiol effect on uterine water uptake was followed with and without concurrent colchicine administration up to 6 h after administration. At no time during this period did there appear to be any influence of colchicine on translocation of the estradiol receptor complex into the nucleus. Examination of physical chemical characteristics of the nuclear estradiol receptr complex after estradiol and estradiol plus colchicine treatments revealed no observable differences. Thus, colchicine inhibition of estradiol-stimulated uterine water retention does not appear to be mediated through inhibition of nuclear translocation of estradiol-receptor complex nor to be due to any reduced retention time of estradiol-receptor complex in uterine nuclei.