title: Estrogen modulates RGS9 expression in the nucleus accumbens.
abstract: Estrogen enhances psychostimulant-induced dopamine receptor-mediated behaviors. One possible mechanism for this enhancement is modulation of the expression of the regulators of G-protein signaling (RGS) proteins. Ovariectomized (OVX) rats received empty s.c. implants or implants packed with 17beta estradiol. Two weeks later the rats were given a single injection of various dopaminergic agents or saline. Estrogen administration to OVX rats selectively reduced RGS9 mRNA expression in the nucleus accumbens shell, but not core. Treating rats with D1 and D2 dopamine receptor agonists or amphetamine failed to change RGS9 mRNA expression in either OVX or OVX rats receiving estrogen. Our findings provide evidence for estrogen as a factor that enhances dopamine receptor signaling by altering RGS9 mRNA expression which could underlie gender specific patterns of psychostimulant abuse.
authors.affiliation: Maryland Psychiatric Research Center, University of Maryland School of Medicine, Baltimore, MD 21228, USA. jsharifi@mprc.umaryland.edu
authors.forename: Jill L
authors.initials: JL
authors.lastname: Sharifi
authors.forename: Dana L
authors.initials: DL
authors.lastname: Brady
authors.forename: James I
authors.initials: JI
authors.lastname: Koenig
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000661:Amphetamine / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001345:Autoradiography / Q000379:methods; D018491:Dopamine Agonists / Q000494:pharmacology; D018765:Dopamine Uptake Inhibitors / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects*; D017403:In Situ Hybridization / Q000379:methods; D009714:Nucleus Accumbens / Q000187:drug effects* / Q000378:metabolism; D010052:Ovariectomy / Q000379:methods; D019257:Quinpirole / Q000494:pharmacology; D020710:RGS Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018491:Dopamine Agonists; D018765:Dopamine Uptake Inhibitors; D020710:RGS Proteins; D012333:RNA, Messenger; C116925:regulator of g-protein signaling 9; D019257:Quinpirole; D004958:Estradiol; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000661:Amphetamine