{"id":24528,"date":"2017-11-02T13:32:17","date_gmt":"2017-11-02T17:32:17","guid":{"rendered":"http:\/\/therapytoronto.ca\/news\/?p=24528"},"modified":"2017-11-07T02:34:01","modified_gmt":"2017-11-07T07:34:01","slug":"prenatal-exposure-to-bpa-at-low-levels-can-affect-gene-expression-in-developing-rat-brain","status":"publish","type":"post","link":"https:\/\/therapytoronto.ca\/news\/2017\/11\/prenatal-exposure-to-bpa-at-low-levels-can-affect-gene-expression-in-developing-rat-brain\/","title":{"rendered":"Prenatal exposure to BPA at low levels can affect gene expression in developing rat brain"},"content":{"rendered":"<p>From the North Carolina State University press release:<\/p>\n<blockquote>\n<p id=\"first\" class=\"lead\"><img loading=\"lazy\" class=\"alignright size-full wp-image-15010\" src=\"http:\/\/therapytoronto.ca\/news\/wp-content\/uploads\/2013\/07\/genetic_blueprint.jpg\" alt=\"\" width=\"225\" height=\"300\" \/>New research from North Carolina State University reveals that <strong>prenatal exposure to bisphenol A (BPA) <\/strong>at levels below those currently considered safe for humans affects<strong> gene expression related to sexual differentiation <\/strong>and<strong> neurodevelopment <\/strong>in the developing rat brain.<\/p>\n<div id=\"text\">\n<p>BPA is a chemical used in a variety of consumer and household products including some food containers. Experimental data has also suggested a <strong>link between the chemical and mood or anxiety-related behaviors in children<\/strong>. Currently, the U.S. Food and Drug Administration (FDA) No Observed Adverse Effect Level (NOAEL) for BPA is 50 micrograms per kilogram of body weight per day.<\/p>\n<p>Heather Patisaul, professor of biology at NC State, with Ph.D. candidate Sheryl Arambula, conducted a study exposing gestating rats to levels of BPA both above and below those currently considered to have no adverse effect &#8212; including levels as low as 2.5 and 25 micrograms per kilogram of body weight per day &#8212; and looked at effects in the brains of their newborn pups.<\/p>\n<p>Arambula and Patisaul found that prenatal BPA exposure, even at the lowest levels, changed the expression of numerous hormone receptors including those for <strong>androgen<\/strong>, <strong>estrogen<\/strong>, <strong>oxytocin <\/strong>and <strong>vasopressin<\/strong> in the newborns&#8217; <strong>amygdala<\/strong>, a <strong>brain structure involved in a wide range of stress and emotional behaviors<\/strong>. Oxytocin, for example, is important for affiliation and pair-bonding, while vasopressin is involved in stress responses. The changes varied depending upon the sex of the newborn and the amount of exposure. Significantly, <strong>disruption of genes critical for synaptic transmission and neurodevelopment were also found to be altered, with females appearing to be more sensitive than males<\/strong>.<\/p>\n<p>&#8220;Uniquely, we found that low level prenatal BPA exposure can change androgen receptor expression levels in the amygdala,&#8221; says Arambula. &#8220;In humans, this gene is important for forming differences between male and female brains, which suggests this could be a way by which BPA exposure might alter sex differences in the human brain.&#8221;<\/p>\n<p>Patisaul is among a consortium of researchers involved in a multi-year, multi-disciplinary project called CLARITY-BPA, a research initiative that includes the FDA, the National Toxicology Program, the National Institute of Environmental Health Sciences (NIEHS), and 13 academic labs. CLARITY-BPA seeks to understand how BPA affects multiple organ systems. Patisaul&#8217;s focus is on brain and behavior. All rats in the study were housed at the National Center for Toxicological Research and followed FDA protocols for exposure. CLARITY-BPA experiments were specifically conceived and conducted to provide the FDA with data it could use to make decisions about human health risks.<\/p>\n<p>&#8220;In our previous work, including work for this consortium, we found similar changes in other brain regions including the hypothalamus and hippocampus.&#8221; says Patisaul. &#8220;There is now a wealth of data showing that BPA can alter neurodevelopment. There is no question that prenatal BPA exposure at levels currently considered safe for humans affects hormone-sensitive gene expression in the developing rodent brain, suggesting that what we consider &#8216;safe&#8217; for human brains may need to be re-evaluated.&#8221;<\/p>\n<p>The researchers&#8217; findings appear in\u00a0<em>NeuroToxicology<\/em>. Arambula is first author and Patisaul is corresponding author of the work. Dereje Jima, a specialist with NC State&#8217;s Center for Human Health and the Environment, did the bioinformatics analysis. The research was funded by the NIEHS (grants P30ES025128 and U011ES020929).<\/p>\n<\/div>\n<\/blockquote>\n<!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"<p>From the North Carolina State University press release: New research from North Carolina State University reveals that prenatal exposure to bisphenol A (BPA) at levels below those currently considered safe&#8230; <a class=\"read-more-link\" href=\"https:\/\/therapytoronto.ca\/news\/2017\/11\/prenatal-exposure-to-bpa-at-low-levels-can-affect-gene-expression-in-developing-rat-brain\/\">Read more &raquo;<\/a><!-- AddThis Advanced Settings generic via filter on get_the_excerpt --><!-- AddThis Share Buttons generic via filter on get_the_excerpt --><\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[356,6],"tags":[42,234,93],"_links":{"self":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/24528"}],"collection":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/comments?post=24528"}],"version-history":[{"count":2,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/24528\/revisions"}],"predecessor-version":[{"id":24561,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/posts\/24528\/revisions\/24561"}],"wp:attachment":[{"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/media?parent=24528"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/categories?post=24528"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/therapytoronto.ca\/news\/wp-json\/wp\/v2\/tags?post=24528"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}