T-Screen as a tool to identify thyroid hormone receptor active compounds

Gutleb, AC; Meerts, IATM; Bergsma, JH; Schriks, M; Murk, AJ

HERO ID

652770

Reference Type

Journal Article

Year

2005

Language

English

PMID

21783481

HERO ID 652770
In Press No
Year 2005
Title T-Screen as a tool to identify thyroid hormone receptor active compounds
Authors Gutleb, AC; Meerts, IATM; Bergsma, JH; Schriks, M; Murk, AJ
Journal Environmental Toxicology and Pharmacology
Volume 19
Issue 2
Page Numbers 231-238
Abstract The T-Screen represents an in vitro bioassay based on thyroid hormone dependent cell proliferation of a rat pituitary tumor cell line (GH3) in serum-free medium. It can be used to study interference of compds. with thyroid hormone at the cellular level, thus bridging the gap between limitations of assays using either isolated mols. (enzymes, transport proteins) or complex in vivo expts. with all the complex feedback mechanisms present. Compds. are tested both in the absence and presence of thyroid hormone (EC50 concn. of T3) to test for both agonistic and antagonistic potency. Thyroid hormones (3,3'-5-triiodothyronine: T3 and 3,3',5,5'-tetraiodothyroxine: T4) and compds. resembling the structure of thyroid hormones (3,3'-5-triiodothyroacetic acid: Triac; 3,3',5,5'-tetraiodothyroacetic acid: Tetrac) induced cell growth, with the rank order Triac > T3 > Tetrac > T4 (relative potency = 1.35>1 > 0.29>0.07), which is identical to published affinities of these compds. for nuclear thyroid hormone receptors. Exposure to 5,5'-diphenylhydantoin (DPH) in the presence of 0.25 nM T3 resulted in up to 60% decreased cell growth at 200 ?M DPH. No effect of DPH on basal metabolic activity of GH3 cells was obsd. at this concn. Fentinchloride (IC50 = 21 nM) decreased cell growth induced by 0.25 nM T3, whereas parallel exposure to these concns. in the absence of T3 did not alter basal metabolic activities of GH3 cells. Apolar sediment exts. from the Dommel (34%) and Terneuzen (14%) decreased cell growth in the presence of 0.25 nM T3, whereas the ext. from Hoogeveen increased cell growth (26%) and the ext. from North Sea Channel had no effect. The T-Screen proved to be a fast and functional assay for assessing thyroid hormone receptor active potencies of pure chems. or environmental mixts.
Doi 10.1016/j.etap.2004.06.003
Pmid 21783481
Wosid WOS:000226642800005
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English
Keyword thyroid hormone disruptor; EDC; bioassay; in vitro