title: Anti-progestogenic effect of flutamide on uterine expression of calbindin-D9k mRNA and protein in immature mice.
abstract: A calcium binding protein, calbindin-D9k (CaBP-9k), is a cytosolic protein and regulated by steroid hormones in the reproductive tissues. Mouse CaBP-9k gene was predominantly regulated by progesterone (P4), whereas rat CaBP-9k was mainly regulated by 17beta-estradiol (E2) in the uterus. The induction of CaBP-9k can be employed as a biomarker for steroidal substrates as endocrine disruptors (EDs). Flutamide (FLU) is a non-steroidal anti-androgen or pro-drug that is rapidly metabolized to hydroxyflutamide, which may have both an anti-androgenic and anti-progestogenic activities. Thus, in the present study, we employed immature mice (14-day-old) subcutaneously injected with P4 (20 mg/kg/day) and/or FLU (5 mg/kg/day) for 3 consecutive days in the presence or absence of RU486, a pure PR antagonist (30 mg/kg/day), to analyze uterine CaBP-9k expression in this model. When immature mice were treated with P4, the expression levels of CaBP-9k mRNA and protein were significantly increased by P4. P4-induced expression levels of CaBP-9k mRNA and protein were abolished by FLU, in part, suggesting that FLU is a partial antagonist of P4 in the regulation of uterine CaBP-9k in immature mice. In addition, P4-induced CaBP-9k expression was completely reversed by RU486. Increased expression levels of CaBP-9k mRNA and protein were maintained for 24h after final injection with P4 in a time-dependent manner. However, CaBP-9k mRNA rapidly disappeared after 48 h and its protein level is similar with its mRNA. Treatment with FLU suppressed partially P4-induced CaBP-9k mRNA and protein until 24 h. Taken together, these results indicate that FLU has an anti-progestogenic activity and plays a role as a partial antagonist of P4 in the regulation of uterine CaBP-9k in immature mouse model.
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea.
authors.forename: Youn-Kyu
authors.initials: YK
authors.lastname: Ji
authors.forename: Geun-Shik
authors.initials: GS
authors.lastname: Lee
authors.forename: Kyung-Chul
authors.initials: KC
authors.lastname: Choi
authors.forename: Eui-Bae
authors.initials: EB
authors.lastname: Jeung
mesh_terms: D000726:Androgen Antagonists / Q000494:pharmacology; D000818:Animals; D015152:Blotting, Northern / Q000379:methods; D015153:Blotting, Western / Q000379:methods; D064026:Calbindins; D004305:Dose-Response Relationship, Drug; D005260:Female; D005485:Flutamide / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D007279:Injections, Subcutaneous; D051379:Mice; D008813:Mice, Inbred ICR; D015735:Mifepristone / Q000737:chemistry / Q000494:pharmacology; D015394:Molecular Structure; D011374:Progesterone / Q000008:administration & dosage / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D064030:S100 Calcium Binding Protein G / Q000096:biosynthesis / Q000235:genetics*; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects / Q000235:genetics; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000726:Androgen Antagonists; D064026:Calbindins; D012333:RNA, Messenger; D064030:S100 Calcium Binding Protein G; C576507:S100g protein, mouse; C576508:S100g protein, rat; C014290:hydroxyflutamide; D015735:Mifepristone; D011374:Progesterone; D005485:Flutamide