Tetrabromobisphenol A disrupts vertebrate development

[helvella]

No. I refuse. I will not explain this paper in simple language. Maybe in a couple of years when I have understood it myself, a bit, then I could have a stab at doing so.

I think it says that a specific flame retardant can affect basic development through embryo stages of vertebrates. That could be you and me.

Don't forget that we also have a wodge of papers about Bisphenol A and its endocrine disrupting capabilities - and that has been used in plastic bottles and tin cans.

Tetrabromobisphenol A disrupts vertebrate development via thyroid hormone signaling pathway in a developmental stage-dependent manner

Yinfeng Zhang , Wei Xu , Qinqin Lou , Yuanyuan Li , Yaxian Zhao , Wuji Wei , Zhanfen Qin , Huili Wang , and Jianzhong Li

Environ. Sci. Technol., Just Accepted Manuscript

DOI: 10.1021/es502366g

Publication Date (Web): June 25, 2014

Copyright © 2014 American Chemical Society

Abstract

Data concerning effects of tetrabromobisphenol A (TBBPA) on thyroid hormone (TH)-dependent vertebrate development have been limited, although TBBPA has been demonstrated in vitro to disrupt the TH signaling pathway at the transcriptional level. In this study, we investigated the effects of TBBPA on T3-induced and spontaneous Xenopus laevis metamorphosis, which share many similarities with TH-dependent development in higher vertebrates. In a 6-day T3-induced metamorphosis assay using pre-metamorphic tadpoles, 101000 nM TBBPA exhibited inhibitory effects on T3-induced expression of TH-response genes and morphological changes in a concentration-dependent manner, with a weak stimulatory action on tadpole development and TH-response gene expression in the absence of T3 induction. In a spontaneous metamorphosis assay, we further found that TBBPA promoted tadpole development from stage 51 to 56 (pre- and pro-metamorphic stages), but inhibited metamorphic development from stage 57 to 66 (metamorphic climax). These results strongly show that TBBPA, even at low concentrations, disrupts TH-dependent development in a developmental stage-dependent manner, i.e., TBBPA exhibits an antagonistic activity at the developmental stages when animals have high endogenous TH levels, whereas it acts as an agonist at the developmental stages when animals have low endogenous TH levels. Our study highlights the adverse influences of TBBPA on TH-dependent development in vertebrates.

pubs.acs.org/doi/abs/10.102...

Full paper available for free if you sign up to the site - for free.

Wiki explains a bit about TBBPA here:

en.wikipedia.org/wiki/Tetra...

Rod

[Clutter]

I hate it when you post stuff I can't pronounce

Sadly the adverse effects of flame retardants have been known for years yet there don't seem to be any attempts to curb use of them. Flame retardants are a classic example of the unintended consequences of trying to mitigate one harm and in the process causing another, perhaps more serious, harm.

[helvella Administrator Thyroid UK in reply to Clutter]

You give me a list of what you can't pronounce and I shall avoid posting about them.

Yes - I know about flame retardants generally, but they are actually only rarely mentioned here, so when this paper popped up it seemed worth posting.

Rod

[mickstability in reply to helvella]

I offer terephthalylidene dicamphor sulfonic acid and its useful monomer cyclohexanedimethanol for starters (it's a UV blocker used in sunscreens).

[helvella Administrator Thyroid UK in reply to mickstability]

Sounds like introductions to the chemists' ball from "I'm sorry I haven't a clue".

I think I can get my tongue around those but we will have to wait for Clutter's response.

[mickstability in reply to helvella]

'Mr and Mrs Chlorinatedbiphenol and their lovely daughter Polly'

[Clutter]

Perhaps I should rephrase and say that I hate not being able to pronounce some of the things you post

Flame retardants are a huge problem as it probably isn't possible to buy soft furnishings with out them.

[Hidden]

This is about bromides and bromine I think. Bromine displaces iodine. Means our thyroids don't get enough...

[helvella Administrator Thyroid UK in reply to Hidden]

The full paper includes this sentence:

With a similar chemical structure to TH, TBBPA has been shown to bind to TR and affect TR mediated gene expression in vitro, exhibiting antagonistic or agonistic effects on TH

actions.

I think that is suggesting that the effect is from the shape (and electrical charges, etc.) of the whole molecule rather than the specific effect of the bromine atoms. It may well be that the TPPBA has this effect because of the bromine atoms, but I don't get the impression that the bromine atoms get broken off and affect the thyroid directly - but maybe they do?

[mistydog]

I refuse to worry about things I cannot affect. I am not putting my head in the sand, but I've tried politics and it's a very long slog. I shall support those who do it, and hope they get somewhere.