2012年9月8日 訊 /生物谷BIOON/ --近日，來自北卡羅來納州立大學(xué)的研究者表示,，年輕時(shí)暴露于化學(xué)雙酚A（BPA）,，可以促使大腦杏仁核特定區(qū)域的基因表達(dá)發(fā)生改變，進(jìn)而引發(fā)機(jī)體高度焦慮癥,。研究者同時(shí)發(fā)現(xiàn)富含大豆的飲食可以緩解高焦慮的表現(xiàn),。相關(guān)研究成果刊登在了9月5日的國(guó)際雜志PLoS One上。
我們都知道BPA可以引發(fā)焦慮,。BPA常用于聚碳酸鹽塑料和環(huán)氧樹脂中,，而且其在消費(fèi)品如食物容器中也常常使用。在文章中,，研究者使鼠類分別在懷孕期間,、哺乳期間以及整個(gè)青春期期間暴露于低劑量的BPA中,，其中一組僅僅以大豆喂食；一組以無大豆食品喂食,；另外一組暴露于BPA中,，且同時(shí)以大豆喂食，最后一組僅僅暴露于BPA中,，不以大豆進(jìn)行喂食,。通過實(shí)驗(yàn)發(fā)現(xiàn)，暴露于BPA中的動(dòng)物,，其血液中的BPA水平和人類一樣維持在一定水平,。類似地，研究者也檢測(cè)了喂食大豆的動(dòng)物血液中染料木黃酮的水平,，發(fā)現(xiàn)其水平也和人類一樣維持在一定范圍之內(nèi),。
在無大豆喂食的青春期鼠中，暴露于BPA的鼠表現(xiàn)出了明顯的高焦慮癥,，研究者同時(shí)發(fā)現(xiàn),，其大腦中基因的改變和焦慮的提高明顯相關(guān)。研究揭示了大腦杏仁核區(qū)域的基因表達(dá)改變和機(jī)體行為改變明顯相關(guān),。其中兩個(gè)受影響的基因是雌激素受體β和黑皮質(zhì)素受體4,，兩個(gè)都是催產(chǎn)素釋放所必須的，然而催產(chǎn)素信號(hào)路徑的改變或許會(huì)促使這種行為的改變,。催產(chǎn)素是一種激素,，其也是一種和社會(huì)行為相關(guān)的神經(jīng)遞質(zhì)。
研究者發(fā)現(xiàn),，給予大豆喂食的青春期鼠類并不會(huì)產(chǎn)生焦慮情緒,，這也就表明，富含大豆的飲食或許會(huì)減緩BPA所帶來的效應(yīng),，但是其具體的分子機(jī)理尚不清楚。研究者Patisaul表示,，大豆中包含有植物雌激素,，其可以影響內(nèi)分泌系統(tǒng)，而內(nèi)分泌系統(tǒng)可以調(diào)節(jié)激素的分泌,。目前是否植物雌激素可以緩解BPA所帶來的效應(yīng),，我們并不清楚，后期研究我們將重點(diǎn)進(jìn)行此項(xiàng)機(jī)理研究,。（生物谷Bioon.com）
編譯自：Study finds how BPA affects gene expression, anxiety; Soy mitigates effects
doi:10.1371/journal.pone.0043890
PMC:
PMID:
Anxiogenic Effects of Developmental Bisphenol A Exposure Are Associated with Gene Expression Changes in the Juvenile Rat Amygdala and Mitigated by Soy
Heather B. Patisaul1,2*, Alana W. Sullivan1,2, Meghan E. Radford1,2, Deena M. Walker3, Heather B. Adewale1,2, Bozena Winnik4, Janis L. Coughlin4, Brian Buckley5, Andrea C. Gore3
Early life exposure to Bisphenol A (BPA), a component of polycarbonate plastics and epoxy resins, alters sociosexual behavior in numerous species including humans. The present study focused on the ontogeny of these behavioral effects beginning in adolescence and assessed the underlying molecular changes in the amygdala. We also explored the mitigating potential of a soy-rich diet on these endpoints. Wistar rats were exposed to BPA via drinking water (1 mg/L) from gestation through puberty, and reared on a soy-based or soy-free diet. A group exposed to ethinyl estradiol (50 µg/L) and a soy-free diet was used as a positive estrogenic control. Animals were tested as juveniles or adults for anxiety-like and exploratory behavior. Assessment of serum BPA and genistein (GEN), a soy phytoestrogen, confirmed that internal dose was within a human-relevant range. BPA induced anxiogenic behavior in juveniles and loss of sexual dimorphisms in adult exploratory behavior, but only in the animals reared on the soy-free diet. Expression analysis revealed a suite of genes, including a subset known to mediate sociosexual behavior, associated with BPA-induced juvenile anxiety. Notably, expression of estrogen receptor beta (Esr2) and two melanocortin receptors (Mc3r, Mc4r) were downregulated. Collectively, these results show that behavioral impacts of BPA can manifest during adolescence, but wane in adulthood, and may be mitigated by diet. These data also reveal that, because ERβ and melanocortin receptors are crucial to their function, oxytocin/vasopressin signaling pathways, which have previously been linked to human affective disorders, may underlie these behavioral outcomes.
