title: RU486 blocks effects of allopregnanolone on the response to restraint stress.
abstract: These experiments were designed to provide information about the potential involvement of progesterone receptors in the ability of allopregnanolone (3α-hydroxy-5α-pregnan-20-one) to reduce the lordosis-inhibiting effects of restraint stress. Ovariectomized Fischer rats were hormonally primed with 10 μg estradiol benzoate and 4 mg/kg allopregnanolone or vehicle. One hour before allopregnanolone, rats were injected with the progesterone receptor antagonist, RU486 (11β-(4-dimethylamino)phenyl-17β-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one), or vehicle. Four hours after allopregnanolone or vehicle, sexual behavior was examined before and after a 5-min restraint stress. Lordosis behavior of rats primed only with estradiol benzoate declined after the 5 min of restraint while allopregnanolone prevented this decline. RU486 attenuated the ability of allopregnanolone to prevent the restraint-induced decline in lordosis behavior. These findings are consistent with earlier suggestions that progesterone receptors are involved in allopregnanolone's ability to reduce the effects of restraint stress.
authors.affiliation: Department of Biology, Texas Woman's University, United States. LUphouse@mail.twu.edu
authors.forename: Lynda
authors.initials: L
authors.lastname: Uphouse
authors.forename: Sarah
authors.initials: S
authors.lastname: Adams
authors.forename: Chandra Suma Johnson
authors.initials: CS
authors.lastname: Miryala
authors.forename: James
authors.initials: J
authors.lastname: Hassell
authors.forename: Cindy
authors.initials: C
authors.lastname: Hiegel
mesh_terms: D000818:Animals; D004347:Drug Interactions; D005260:Female; D008297:Male; D015735:Mifepristone / Q000494:pharmacology*; D011187:Posture; D011280:Pregnanolone / Q000037:antagonists & inhibitors* / Q000494:pharmacology / Q000627:therapeutic use; D051381:Rats; D011916:Rats, Inbred F344; D011980:Receptors, Progesterone / Q000037:antagonists & inhibitors* / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology; D013315:Stress, Psychological / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology
chemical_list: D011980:Receptors, Progesterone; D015735:Mifepristone; D011280:Pregnanolone