1. Vinclozolin andp,p′-DDE Alter Androgen-Dependent Gene Expression:In VivoConfirmation of an Androgen Receptor-Mediated Mechanism
- Author
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Roberts Kp, Leon Earl Gray, William R. Kelce, and Christy R. Lambright
- Subjects
Male ,endocrine system ,medicine.medical_specialty ,medicine.drug_class ,Dichlorodiphenyl Dichloroethylene ,Secretoglobins ,Toxicology ,Antiandrogen ,Androgen-Binding Protein ,Flutamide ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Seminal vesicle ,In vivo ,Internal medicine ,medicine ,Animals ,Uteroglobin ,Testosterone ,RNA, Messenger ,Vinclozolin ,Receptor ,Oxazoles ,Glycoproteins ,Drug Implants ,Pharmacology ,Prostatein ,Prostate ,Seminal Vesicles ,Androgen Antagonists ,Organ Size ,Rats ,Androgen receptor ,Clusterin ,medicine.anatomical_structure ,Endocrinology ,Gene Expression Regulation ,chemistry ,Receptors, Androgen ,Orchiectomy ,Molecular Chaperones - Abstract
Vinclozolin and p,p'-DDE induce antiandrogenic developmental effects in vivo and are potent inhibitors of androgen receptor (AR) binding and AR-dependent gene expression in vitro. To determine whether this molecular mechanism is operative in vivo, the effects of these compounds on two androgen-regulated prostatic mRNAs were studied. Rats were sham operated or castrated and immediately implanted with one or two empty 2.5-cm silastic capsules or with one (1x) or two (2x) 2.5-cm capsules containing testosterone (T). T-implanted rats were treated by gavage for 4 days with vehicle (corn oil), vinclozolin (200 mg/kg/day), p,p'-DDE (200 mg/kg/day), or the antiandrogen flutamide (100 mg/kg/day) as a positive control. Vinclozolin, p,p'-DDE, and flutamide all induced a reciprocal decline in seminal vesicle (p < 0.01) and prostate (p < 0.01) weight as well as a reduction in immunohistochemical staining of AR in epididymal nuclei compared to vehicle-treated T-implanted controls. Specific AR antagonism was assessed by determining the ability of these chemicals to induce a testosterone-repressed prostatic message (i.e., TRPM-2) and/or repress a testosterone-induced prostatic message (i.e., prostatein subunit C3). Densitometry scans of Northern blots indicated that vinclozolin, p,p'-DDE, and flutamide each induced TRPM-2 mRNA and repressed C3 mRNA compared to vehicle-treated T-implanted controls. These antiandrogenic effects were competitively reduced in castrate rats implanted with two 2.5-cm T capsules (2x), where serum T levels were elevated more than twofold above physiological levels. Taken together, these data indicate that vinclozolin and p,p'-DDE act as antiandrogens in vivo by altering the expression of androgen-dependent genes.
- Published
- 1997
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