Dihydrotestosterone and estrogen regulation of rat brain androgen-receptor immunoreactivity.
Androgen-receptor upregulation that occurs with androgenic-anabolic steroid (AAS) administration may be mediated by AAS metabolites, dihydrotestosterone (DHT), and estrogen. Castrated and intact male rats received 14 s.c. daily injections of AAS (2 mg/kg testosterone cypionate, 2 mg/kg nandrolone decanoate, and 1 mg/kg boldenone undecylenate in sesame oil vehicle), DHT (5 mg/kg dihydrotestosterone), EB (5 mg/kg estradiol benzoate), or sesame oil vehicle. Approximately 18-24 h after the fourteenth injection, brain tissues were removed and processed immunocytochemically using the PG-21 androgen-receptor antibody. As reported before, castration eliminated AR-ir (androgen-receptor immunoreactivity) and AAS upregulated AR-ir in the ventromedial hypothalamus (VMHVL), medial amygdala (MePV), and medial preoptic area (MPOM). When compared to AAS, DHT fully upregulated AR-ir in the VM VL and MPOM and partially upregulated AR-ir in the MePV. EB treatment partially upregulated AR-ir in the VMHVL and MePV, but not in the MPOM of castrated rats. Because AR-ir in the MPOM was consistently upregulated by DHT or AAS, and not EB, androgen-receptor availability in this region may be mediated specifically via androgen receptors.
Department of Psychology, University of Louisiana, P.O. Box 43131, Lafayette, LA 70504, USA. csm5689@usl.edu
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D000679:Amygdala / Q000187:drug effects / Q000378:metabolism; D045930:Anabolic Agents / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002452:Cell Count / Q000187:drug effects; D013196:Dihydrotestosterone / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008297:Male; D009277:Nandrolone / Q000031:analogs & derivatives* / Q000494:pharmacology; D000077603:Nandrolone Decanoate; D011301:Preoptic Area / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D011944:Receptors, Androgen / Q000378:metabolism*; D013739:Testosterone / Q000031:analogs & derivatives* / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects; D014697:Ventromedial Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism
D045930:Anabolic Agents; D004967:Estrogens; D011944:Receptors, Androgen; D013196:Dihydrotestosterone; D013739:Testosterone; D009277:Nandrolone; D000077603:Nandrolone Decanoate; C016131:testosterone 17 beta-cypionate; C001371:boldenone undecylenate