title: Density of mu-opioid receptors in the hippocampus of adult male and female rats is altered by prenatal morphine exposure and gonadal hormone treatment.
abstract: The present in vitro autoradiography study demonstrates that prenatal exposure to morphine alters the density of mu-opioid receptors in the hippocampus of adult female but not adult male rats. Prenatal morphine exposure increased the mu-opioid receptor density in the CA1 of ovariectomized (OVX) females and in the CA3 of OVX, estradiol benzoate-plus progesterone (EB+P)-treated females, but decreased it in CA3 of OVX females. There were also hormonal effects on mu-opioid receptor density in adult female rats. In the CA1, only morphine-exposed but not saline-exposed, hormone-treated females (EB, P, or EB+P) had a decrease in mu-opioid receptor density relative to OVX females. Both saline-exposed and morphine-exposed, OVX females after gonadal hormone replacement had a lower density of mu-opioid receptors in the CA3 and in the dentate gyrus (DG) than OVX females. In male rats, there was a decrease in mu-opioid receptor density in the CA1 and CA3 of gonadectomized (GNX), testosterone 17beta-proprionate (TP)-treated males relative to GNX males regardless of prenatal morphine exposure. In the DG, the mu-opioid receptor density was reduced only in morphine-exposed but not in saline-exposed, TP-treated males compared with GNX males. Thus, our data demonstrate that mu-opioid receptor density in the hippocampus is affected by prenatal morphine exposure and by male and female gonadal hormones.
authors.affiliation: Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
authors.forename: Romana
authors.initials: R
authors.lastname: Slamberová
authors.forename: Agnes
authors.initials: A
authors.lastname: Rimanóczy
authors.forename: Noffar
authors.initials: N
authors.lastname: Bar
authors.forename: Cheryl J
authors.initials: CJ
authors.lastname: Schindler
authors.forename: Ilona
authors.initials: I
authors.lastname: Vathy
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D004967:Estrogens / Q000172:deficiency / Q000494:pharmacology; D005260:Female; D012739:Gonadal Steroid Hormones / Q000172:deficiency* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D008297:Male; D009020:Morphine / Q000009:adverse effects*; D009021:Morphine Dependence / Q000150:complications*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009919:Orchiectomy; D010052:Ovariectomy; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D011374:Progesterone / Q000172:deficiency / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017450:Receptors, Opioid, mu / Q000187:drug effects* / Q000378:metabolism; D012727:Sex Characteristics; D013739:Testosterone / Q000172:deficiency / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D004967:Estrogens; D012739:Gonadal Steroid Hormones; D017450:Receptors, Opioid, mu; D013739:Testosterone; D011374:Progesterone; D009020:Morphine