Effects of copper on cytoplasmic and nuclear binding of 17 beta-estradiol in the rat uterus.
Interference of Cu++ with the initial events in estrogen action was tested by determining Cu++ effects on estradiol-receptor interactions. When immature rat uteri were incubated in vitro with [3H] estradiol ([3H]E2), steroid was bound in cytoplasmic fractions and rapidly accumulated in the nuclear fraction in a manner which was dependent upon time and hormone concentration. Uteri which were preincubated with 2 X 10(-4) M CuCl2 for 40-60 min and then exposed to [3H]E2 were found to have a 30-50% decrease in the amount of steroid bound in the cytoplasmic and nuclear fractions. When copper-treated uteri were exposed to [3H]E2 for variable times, the quantity of steroid bound in the cytoplasmic fraction was markedly depressed and the rate of nuclear accumulation of [3H]E2 was significantly decreased. These results show that Cu++ can inhibit [3H]E2 binding to tissue cytoplasmic receptors in vitro and thereby interfere with hormone delivery to target cell nuclei.
D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D003300:Copper / Q000494:pharmacology*; D003593:Cytoplasm / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D051381:Rats; D011959:Receptors, Estradiol / Q000187:drug effects / Q000378:metabolism; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
D011959:Receptors, Estradiol; D004958:Estradiol; D003300:Copper