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.
Highlights
Interfering with the physiologic endocrine system of an organism can lead to serious problems
Protein expression of CaBP-9K was similar to the mRNA levels, the basal expression levels of CaBP-9k was lower by showing faint band (Figure 1b)
Immature rats were administrated with Ethinyl estradiol (EE) and D4, and the uterine weight was measured to confirm the estrogenic effect of D4 following the OECD guidelines
Summary
Interfering with the physiologic endocrine system of an organism can lead to serious problems. Compounds produced for daily use are less stringently evaluated compared to pharmaceuticals These materials are not directly absorbed by an organism, they can have potent indirect effects. Many synthetic compounds such as plasticizers or other brominated flame retardants have been defined as endocrine disruptors (EDs) that generally have estrogenic activity in humans [4]. Polycystic ovary syndrome (PCOS) has been shown to be related to EDs [8] Due to their estrogen-disrupting properties, some chemicals are banned in various nations. We evaluated the estrogenic effect of D4 on GH3 rat pituitary gland cells by measuring the expression levels of CaBP-9K, a well-established biomarker for estrogenicity. An uterotrophic (UT) assay was performed following the Organization for Economic Co-operation and Development (OECD) guide for standard comparison and drug administration route
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
