Department of Integrative Neurophysiology, Chiba University Graduate School of Medicine, Japan.
Chemosphere. 2010 Feb;78(7):894-906. doi: 10.1016/j.chemosphere.2009.11.010. Epub 2009 Dec 14.
To examine whether exposure to bisphenol A (BPA) at low levels affect brain function, monoamine concentrations in hippocampus, striatum and brain stem, were investigated in neonatal male rats injected intracranially with BPA at 0-10microgkg(-1). Significant increases of serotonin (5-HT) in hippocampus, 5-HIAA and 5-HIAA/5-HT in brain stem, dopamine (DA) and DOPAC in striatum were observed at 28d after the injection on postnatal day 2. At 7d after the injection, increases in 5-HT and norepinephrine (NE) and decreases in DOPAC and 5-HIAA were observed in hippocampus. To investigate the degradation of BPA in brain, we also measured BPA concentrations of whole neonatal rat brain. Free BPA disappeared from brain tissues within 5h, even when the highest dose (1000microgkg(-1)) was injected. The present results suggest that BPA exposure at lower doses than environmentally relevant levels may have a great impact on monoamine levels in neonatal brain over 28d after its disappearance.
为了研究低水平的双酚 A（BPA）暴露是否会影响大脑功能，研究人员向新生雄性大鼠的颅内注射了 0-10μg/kg 的 BPA，检测了其海马体、纹状体和脑干中单胺的浓度。在注射后第 28 天，即出生后第 2 天，观察到海马体中血清素（5-HT）、脑干中 5-羟吲哚乙酸（5-HIAA）和 5-HIAA/5-HT、纹状体中多巴胺（DA）和 DOPAC 的显著增加。在注射后 7 天，海马体中 5-HT 和去甲肾上腺素（NE）增加，DOPAC 和 5-HIAA 减少。为了研究 BPA 在大脑中的降解情况，我们还测量了新生大鼠全脑的 BPA 浓度。即使注射了最高剂量（1000μg/kg），5 小时内脑组织中的游离 BPA 也会消失。本研究结果表明，BPA 暴露剂量低于环境相关水平，可能会对 BPA 消失后 28 天内新生大脑中单胺水平产生重大影响。
