Schmitt Emily E, Vellers Heather L, Porter Weston W, Lightfoot J Timothy
1Department of Health and Kinesiology, Texas A&M University, College Station, TX; and 2Interdisciplinary Faculty of Toxicology, Texas A&M University, College Station, TX.
Med Sci Sports Exerc. 2016 Jul;48(7):1251-8. doi: 10.1249/MSS.0000000000000908.
Voluntary physical activity levels are regulated by sex hormones. The purpose of this study was to determine the effect of the endocrine disruptor benzyl butyl phthalate (BBP) on the regulation of physical activity in mice.
Mouse dams were treated with 500 mg·kg·d of BBP or vehicle on gestation days 9-16. Pups were weaned and analyzed for voluntary physical activity levels, puberty development, sex hormone levels, and body composition during the 20-wk period.
Seventy-three offspring from BBP-treated dams were studied (n = 43 males and n = 30 females). Endocrine disruption was indicated by decreased anogenital distances in BBP-treated male offspring at 10 (P = 0.001) and 20 wk (P = 0.038) and delayed vaginal openings in BBP-treated female offspring (P = 0.001). Further, there was a significant decrease in serum testosterone concentration in male mice between control and BBP at 10 wk (P = 0.039) and at 20 wk (P = 0.022). In female mice, there was a significant increase in serum testosterone concentration in BBP mice at 20 wk (P = 0.002) and a significant increase in estrogen (estradiol) concentrations at 20 wk in the control female mice (P = 0.015). Overall, BBP mice ran significantly less distance (males, P = 0.008; females, P = 0.042) than controls. Other than a significant increase in BBP-treated males in fat mass at 20 wk (P = 0.040), there was no significant decrease in weight, lean mass, or fat mass in either female or male mice, regardless of treatment.
Maternal endocrine disruption altered hormone response, but not body composition in either sex of offspring, with a corresponding decreased activity throughout early adulthood in all offspring. These results suggest that exposure to common environmental endocrine disruptors in utero can reduce and alter physical activity levels in offspring.
自愿性身体活动水平受性激素调节。本研究的目的是确定内分泌干扰物邻苯二甲酸苄基丁酯（BBP）对小鼠身体活动调节的影响。
在妊娠第9至16天，给母鼠腹腔注射500mg·kg·d的BBP或赋形剂。幼崽断奶后，在20周内对其自愿性身体活动水平、青春期发育、性激素水平和身体组成进行分析。
对73只来自接受BBP处理的母鼠的后代进行了研究（n = 43只雄性和n = 30只雌性）。在10周（P = 0.001）和20周（P = 0.038）时，接受BBP处理的雄性后代肛门与生殖器之间的距离减小，接受BBP处理的雌性后代阴道开口延迟（P = 0.001），这表明存在内分泌干扰。此外，在10周（P = 0.039）和20周（P = 0.022）时，雄性小鼠血清睾酮浓度在对照组和BBP组之间存在显著下降。在雌性小鼠中，20周时BBP组小鼠血清睾酮浓度显著升高（P = 0.002），而对照组雌性小鼠在20周时雌激素（雌二醇）浓度显著升高（P = 0.015）。总体而言，BBP组小鼠的跑步距离显著短于对照组（雄性，P = 0.008；雌性，P = 0.042）。除了在20周时接受BBP处理的雄性小鼠脂肪量显著增加（P = 0.040）外，无论处理如何，雌性或雄性小鼠的体重、瘦体重或脂肪量均无显著下降。
母体内分泌干扰改变了后代两性的激素反应，但未改变身体组成，所有后代在成年早期的活动相应减少。这些结果表明，子宫内暴露于常见的环境内分泌干扰物会降低并改变后代的身体活动水平。
