title: Induction of the Estrogenic Marker Calbindn-D₉k by Octamethylcyclotetrasiloxane.
abstract: Interrupting the hormonal balance of an organism by interfering with hormones and their target receptors gives rise to various problems such as developmental disorders. Collectively, these reagents are known as endocrine disruptors (EDs). Cyclic volatile methyl siloxanes (cVMSs) are a group of silicone polymers that including octamethylcyclotetrasiloxane (D4). In the present study, we examined the estrogenicity of D4 through in vitro and in vivo assays that employed calcium-binding protein 9K (calbindin-D9k; CaBP-9K) as a biomarker. For in vitro investigation, GH3 rat pituitary cells were exposed to vehicle, 17β-estradiol (E2), or D4 with/without ICI 182 780 (ICI). CaBP-9K and progesterone receptor (PR) both were up-regulated by E2 and D4 which were completely blocked by ICI. Transcription of estrogen receptor α (ER α) was decreased by E2 and D4 but increased by ICI. D4 was also administered to immature female rats for an uterotrophic (UT) assay and detection of CaBP-9K. Ethinyl estradiol (EE) or D4 was administered subcutaneously with or without ICI. Although uterine weight was not significant altered by D4, an effect thought to be due to cytochrome P450 (CYP), it induced CaBP-9K and PR gene expression. Based on these results we reveal that D4 has estrogenic potential proven under in vitro and in vivo experimental conditions.
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 362-763, Korea. eastdaylight@gmail.com.
authors.forename: Dongoh
authors.initials: D
authors.lastname: Lee
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 362-763, Korea. prac@naver.com.
authors.forename: Changhwan
authors.initials: C
authors.lastname: Ahn
authors.affiliation: Department of Biomaterials Science, College of National Resources & Life Science, Pusan National University, Miryang, Gyeongsangnam-do 627-706, Korea. anbs@pusan.ac.kr.
authors.forename: Beum-Soo
authors.initials: BS
authors.lastname: An
authors.affiliation: Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 362-763, Korea. ebjeung@chungbuk.ac.kr.
authors.forename: Eui-Bae
authors.initials: EB
authors.lastname: Jeung
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood*; D064026:Calbindins / Q000097:blood*; D052244:Endocrine Disruptors / Q000009:adverse effects*; D065171:Estrogen Receptor Antagonists / Q000097:blood*; D005260:Female; D051381:Rats; D017207:Rats, Sprague-Dawley; D012833:Siloxanes / Q000009:adverse effects*; D014599:Uterus / Q000187:drug effects*
chemical_list: D015415:Biomarkers; D064026:Calbindins; D052244:Endocrine Disruptors; D065171:Estrogen Receptor Antagonists; D012833:Siloxanes; C024064:octamethylcyclotetrasiloxane
keywords: GH3 cell; calbindin-D9k; endocrine disruptors; octamethylcyclotetrasiloxane; uterotrophic assay