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Radwa presented her poster at Neuroscience open House (NSP 2017) at Beckman Institution, Illinois University 

Radwa presented her poster at Neuroscience open House (NSP 2017) at Beckman Institution, Illinois University.
(title: Disruption of Hypothalamic-pituitary testicular axis by prenatal exposure to DEHP induces neurodegeneration in brain and anxiety like behavior on male mice.)

Phthalates are a family of synthetic chemicals that are widely used in medical, automotive and consumer products. Di-(2-ethylhexyl) phthalate (DEHP) is the most commonly used phthalate and it poses a public health concern because it is an endocrine disruptor and acts as an anti-androgen. Maternal exposure to phthalates is a major source of exposure in humans, and DEHP has been detected in amniotic fluid, umbilical cord blood and other bodily fluids. This study tested an ongoing hypothesis that prenatal exposure to DEHP alter neuronal development in male mice. Pregnant female CD-1 mice were orally dosed with 20 μg, 200 μg, 500 mg, or 750 mg/kg/day or vehicle (tocopherol-stripped corn oil) from gestation day 11 until birth. All the DEHP treated groups displayed a significantly reduced fertility, a lower serum testosterone concentration, higher serum estradiol concentration and LH concentration compared to control group at 22 months. Indicating the adverse effect of DEHP on gonadal steroidogenesis and alter the hypothalamic-pituitary-testicular axis. Behavioral tests were performed at the ages of 16-17 months. Elevated plus maze test and open field test found that mice in the 750 mg/kg/day dose group displayed a slightly increased latency to open arm time (p=0.19) and a significantly decreased numbers of entries to center square zone (p=0.014), suggesting a sign of increased anxiety level. These mice spent shorter time exploring a novel object in their novel object exploration test than control mice (P=0.05), indicating impaired memory function. No changes in brain weight, but a significant increase in pituitary weight was seen in DEHP treated group (P=0.005). Pituitary histology was performed to assess the impact of prenatal DEHP exposure to pituitary development. Interestingly, the 750 mg/kg/day DEHP groups showed abnormal cyst formation filled with fluid in the anterior lobe of pituitary (60%). Furthermore, the gonadotrophs expression in anterior pituitary significantly increased in DEHP treated groups (P=0.04). In the brain, the CA1 and CA3 regions of the hippocampus showed a significant decreased in number of pyramidal neurons in all DEHP-treated groups than control group (P=0.01), with an indication of neuronal degeneration. In summary, this study finds that the prenatal exposure to DEHP have a major impact on the male reproductive axis and neuronal cell survival.

02/14/2017