These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: 1-(o-Chlorophenyl)-1 (p-chlorophenyl)2,2,2-trichloroethane induces functional progestin receptors in the rat hypothalamus and pituitary gland.
    Author: Brown TJ, Blaustein JD.
    Journal: Endocrinology; 1984 Dec; 115(6):2052-8. PubMed ID: 6499760.
    Abstract:
    A recent report suggests that estrogen induction of hypothalamic progestin receptors is not a prerequisite for the facilitation by progesterone of female sexual behavior in rats. Progesterone was found to facilitate sexual behavior despite no apparent induction of progestin receptors by 1-(o-chlorophenyl) 1-(p-chlorophenyl)2,2,2-trichloroethane (o,p'-DDT). To investigate these findings further, ovariectomized rats were treated with daily injections of o,p'-DDT for 3 days, followed by progesterone on day 4. Daily injections of 400 mg o,p'-DDT/kg resulted in activation of lordosis in 50% of the animals; injections of 200 mg/kg were ineffective. Cytoplasmic and nuclear progestin receptor levels in the mediobasal hypothalamus-preoptic area and pituitary gland were then determined in similarly treated animals. Because competition assays revealed that o,p'DDT interacts with progestin-binding sites in vitro, residual o,p'-DDT was removed from the cytosol fraction before assay. o,p'-DDT treatment increased the level of cytoplasmic progestin receptors by 43% compared with that in oil-injected controls. Progesterone administration to DDT-treated rats resulted in a 137% increase in the level of nuclear progestin receptors relative to levels observed in animals receiving no progesterone. These findings contradict a previous report using o,p'-DDT and support the hypothesis that estrogen-induced progestin receptors are required for the facilitation of sexual receptivity by progesterone.
    [Abstract] [Full Text] [Related] [New Search]