母鼠孕期暴露双酚A对子代雌性大鼠性发育的影响

目的：研究母鼠孕期暴露双酚A（BPA）对子代雌性大鼠的性发育影响。方法：选择SPF级12周龄的健康成年SD大鼠,按雌∶雄为2∶1比例合笼。将妊娠大鼠20只,随机分成4组,于妊娠第5天至第20天,分别按0,10,50,250mg/（kg·d）进行灌胃染毒。母鼠正常分娩,雌性仔鼠出生28天开始观察阴道开口,第一次发情周期,此后连续观察动情周期变化,在第10周确定发情间期后处死动物。称量肝脏、肾脏、子宫、卵巢的重量,计算脏器系数;用ELISA法测血清中卵泡刺激素（FSH）、黄体生成素（LH）、孕酮（P4）、雌二醇（E2）及睾酮（T）水平。结果：各剂量组肝脏和肾脏重量与对照组相比有增加趋势,50 mg/kg组的肾脏重量和250 mg/kg组的肾脏系数有统计学意义（P〈0.05）;与对照组比较,10 mg/kg组阴道开口延迟,而250 mg/kg组阴道开口日龄提前,各剂量组阴道开口时体重增加（P〈0.05）;与对照组相比,BPA各剂量组子代雌性大鼠性周期均无明显影响;各剂量组与对照组相比,T水平明显下降（P〈0.05）;50mg/kg组与对照组相比,LH、FSH、E2水平明显减少（P〈0.05）,且P4水平有升高趋势;而250 mg/kg组上述指标与对照组比较差异无显著性（P〉0.05）。结论：母鼠孕期暴露BPA可能导致子代雌性大鼠下丘脑-垂体-性腺轴的调节功能障碍,对其性发育功能造成一定影响。     

南昌市行为问题儿童血清双酚A、性激素水平调查

目的 了解南昌市学龄儿童行为问题发生情况及与双酚A(BPA)、性激素的相关性。方法 调查南昌市4所小学的176名7~11岁儿童,由家长统一填写调查问卷表及Conners父母问卷调查表。采用ELISA法测定血清BPA含量,采用直接化学发光法测定血清中黄体生成素(LH)、卵泡刺激素(FSH)、雌二醇(E2)、睾酮(T)含量。结果 176名调查儿童行为问题检出率为19.3%,其中心身问题检出率最高(6.8%);男童学习问题和多动指数检出率高于女童;8岁儿童行为问题检出率最高;血清BPA水平是儿童焦虑的独立预测因素(β=0.172);母亲文化程度高中及以上和高性激素水平(E2和T)是儿童行为问题的独立保护因素(OR母亲文化=0.649;OR性激素=0.801)。结论 南昌市学龄儿童行为问题发生率较高,提高母亲文化程度、减少BPA暴露和控制性激素水平降低有助于减少儿童行为问题的发生。     

Bisphenol-A interferes with estradiol-mediated protection in osteoarthritic chondrocytes

Aged women have a higher risk of osteoarthritis (OA) due to estrogen (E2) loss at menopause. Studies suggested that E2 inhibits nuclear factor (NF)-κB activity which is increased in arthritis pathogenesis. Other studies revealed that external E2 reduces the expression of matrix metalloproteinases (MMPs) in osteoarthritic chondrocytes, and attenuates the pathogenesis of OA. Bisphenol-A (BPA) is an important industrial material, and an endocrine-disrupting chemical (EDC) that binds E2 receptors and interrupts the hormone signaling. It is unknown how BPA affects E2 functions and influences E2-mediated protections in OA. In this study, we investigated the effects of E2 and BPA on nitric oxide (NO) production, NF-κB activation, and MMP-1 expression in chondrosarcoma SW1353 cells and primary human osteoarthritic chondrocytes. Among the tested chemicals, BPA reduced NO production and cell viability of chondrosarcoma cells, but had little effects on osteoarthritic chondrocytes. Using HPLC–UV, we observed BPA in the serum and synovial fluid of OA patients. In primary chondrocytes, modest concentrations of E2 reduced interleukin (IL)-1β-dependent NF-κB activation and MMP-1 expression. BPA antagonized these protective effects of E2 in a concentration-dependent manner. In conclusion, BPA interferes with E2's functions in chondrocytes and may promote OA.     

Bisphenol-A in Artificial Indoor Streams: I. Fate and Effects on Aufwuchs

The disappearance (DT₅₀) from water-phase and effects on aufwuchs of three nominal concentrations (5, 50 and 500 g/l) of bisphenol-A (BPA) were investigated in artificial indoor streams over a period of 103 days. HPLC was used for analyses of BPA in water. Because of the disappearance of BPA from the water-phase, a pulse dosed exposure in weekly intervals was established. At the beginning of the exposure, a lag-phase of 3–8 days was noted. Afterwards DT₅₀ values (time, when 50% of initial BPA disappeared) were about 1 day with no clear trend to lower values during the experiment. The dynamics of aufwuchs was investigated on artificial substrates (unglazed ceramic tiles) in l4-day intervals and quantified by ash free dry weight (AFDW). As an ecotoxicological endpoint the area under the biomass/time curve (AUC) was calculated for: (a) the absolute AFDW-values and (b) values as percentage of start biomass (value of day-2 set as 100%). The reduction of AUC by 10% (EC₁₀) and 50% (EC₅₀) for absolute values was 11 g/l (nominal: 38) and 46 g/l (450), respectively; for values as percentage of start biomass: EC₁₀ 20 g/l (239) and EC₅₀ 73 g/l (806). These values are 20–70-fold lower compared to results from standard algae tests (E_bC, 96 h).