Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)

Editor

Personal info

View

About

Terms

Javascript disabled

Please enable Javascript support in your browser to use this application.

Instructions on how to enable JavaScript on different browsers can be found here: http://www.google.com/support/bin/answer.py?answer=23852.

[edit this page]

Kitamura, S. et al.

Kitamura, Jinno, Suzuki, Sugihara, Ohta, Kuroki, Fujimoto,

Thyroid hormone-like and estrogenic activity of hydroxylated PCBs in cell culture.

The thyroid hormone-disrupting activity of hydroxylated PCBs was examined. 4-Hydroxy-2,2',3,4',5,5'-hexachlorobiphenyl (4-OH-2,2',3,4',5,5'-HxCB), 4-hydroxy-3,3',4',5-tetrachlorobiphenyl (4-OH-3,3',4',5-TCB) and 4,4'-dihydroxy-3,3',5,5'-tetrachlorobiphenyl (4,4'-diOH-3,3',5,5'-TCB), which have been detected as metabolites of PCBs in animals and humans, and six other 4-hydroxylated PCBs markedly inhibited the binding of triiodothyronine (1x10(-10)M) to thyroid hormone receptor ( TR) in the concentration range of 1 x 10(-6) to 1 x 10(-4) M. However, 4-hydroxy-2',4',6'-trichlorobiphenyl (4-OH-2',4',6'-TCB), 3-hydroxy-2,2',5,5'-tetrachlorobiphenyl, 4-hydroxy-2,2',5,5'-tetrachlorobiphenyl, 4-hydroxy-2,3,3',4'-tetrachlorobiphenyl, 2,3',5,5'-tetrachlorobiphenyl and 2,3',4',5,5'-pentachlorodiphenyl did not show affinity for TR. The thyroid hormonal activity of PCBs was also examined using rat pituitary cell line GH3 cells, which grow and release growth hormone in a thyroid hormone-dependent manner. 4-OH-2,2',3,4',5,5'-HxCB, 4,4'-diOH-3,3',5,5'-TCB and 4-OH-3,3',4',5-TCB enhanced the proliferation of GH3 cells and stimulated their production of growth hormone in the concentration range of 1 x 10(-7) to 1 x 10(-4) M, while PCBs which had no affinity for thyroid hormone receptor were inactive. In contrast, only 4-OH-2',4',6'-TCB exhibited a significant estrogenic activity using estrogen-responsive reporter assay in MCF-7 cells. However, the 3,5-dichloro substitution of 4-hydroxylated PCBs markedly decreased the estrogenic activity. These results suggest that, at least for the 17 PCB congeners and hydroxylated metabolites tested, a 4-hydroxyl group in PCBs is essential for thyroid hormonal and estrogenic activities, and that 3,5-dichloro substitution favors thyroid hormonal activity, but not estrogenic activity.[1]

References

Thyroid hormone-like and estrogenic activity of hydroxylated PCBs in cell culture. Kitamura, S., Jinno, N., Suzuki, T., Sugihara, K., Ohta, S., Kuroki, H., Fujimoto, N. Toxicology (2005) [Pubmed]

Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenes Open Access Licence Privacy Policy Terms of Use apsburg

The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.