Estradiol receptor activity in uteri of pregnant mice given lead before implantation.
Lead chloride given intravenously to mice on day 4 of pregnancy has been shown previously to inhibit implantation that normally occurs on the following day. The effect of such lead treatment on the estradiol receptor activity in uterine cytosol from day 5 of pregnancy was investigated. The quantity of estradiol receptors, expressed per uterus, per wet weight of uterine tissue, and per amount of protein, was significantly (P < 0.001) larger in lead-treated animals than in control animals. The estradiol receptor binding affinities were similar for both groups. A possible relationship between the increased estradiol receptor activity and implantation failure in the lead-treated mice is discussed. In vitro addition of 1 and 5 mmoles of lead chloride/liter of cytosol resulted in reduced estradiol binding, which is in accord with previous reports. However, our study indicates that this reduction is due to co-precipitation of lead and receptor proteins.
D000818:Animals; D003600:Cytosol / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D010064:Embryo Implantation; D004958:Estradiol; D005260:Female; D007854:Lead / Q000494:pharmacology*; D051379:Mice; D011247:Pregnancy; D011960:Receptors, Estrogen / Q000187:drug effects*; D014599:Uterus / Q000187:drug effects*
D011960:Receptors, Estrogen; D007854:Lead; D004958:Estradiol