Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29631, United States.
Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29631, United States; Environmental Toxicology Graduate Program, Clemson University, 132 Long Hall, Clemson, SC 29631, United States.
Aquat Toxicol. 2014 Jan;146:196-204. doi: 10.1016/j.aquatox.2013.11.010. Epub 2013 Nov 24.
Arsenic is a contaminant of drinking water and has been correlated with adverse developmental outcomes such as low birth weight, reduced weight gain, and altered locomotor activity. Previous research has shown that killifish (Fundulus heteroclitus) exposed to high arsenic levels during embryogenesis had smaller muscle fiber diameters. The current study was designed to determine whether changes in muscle fibers persisted, were exacerbated, or resolved over time. Killifish embryos were exposed to 0-5 ppm arsenite and, upon hatching, were transferred into either clean water or continued receiving the same exposure to arsenic for up to 16 weeks. Arsenic significantly decreased the weight of both embryonic-only exposed juveniles and continuously exposed juveniles between 4 and 16 weeks of development at concentrations as low as 0.8 ppm. Although arsenite exposure increased the percentage of small diameter fibers during the early weeks, fiber diameters returned to control levels in the embryonic-only exposed fish. However, muscle fiber density was still reduced to 85.7%, 80.3%, and 73.8% of control for the 0.8, 2, and 5 ppm embryonic-only exposure groups, respectively, even after 16 weeks of development. These results indicate that while continuous exposure to arsenic may alter the size of muscle fibers, embryonic-only exposure to arsenic has lasting effects on the number of muscle fibers formed.
砷是饮用水的污染物，与不良发育结果相关，如低出生体重、体重增长减少和运动活动改变。先前的研究表明，在胚胎发生期间暴露于高砷水平的食蚊鱼（Fundulus heteroclitus）肌肉纤维直径较小。本研究旨在确定肌肉纤维的变化是否持续存在、恶化或随时间缓解。食蚊鱼胚胎在胚胎发生期间暴露于 0-5 ppm 的亚砷酸盐，孵化后，将其转移到清洁水中，或继续接受相同浓度的砷暴露，最多可达 16 周。砷在浓度低至 0.8 ppm 时，在胚胎暴露和持续暴露的幼鱼中，从第 4 周到第 16 周，体重显著下降。尽管亚砷酸盐暴露在早期几周内增加了小直径纤维的百分比，但在仅胚胎暴露的鱼类中，纤维直径恢复到对照水平。然而，肌肉纤维密度仍分别减少到对照组的 85.7%、80.3%和 73.8%，对于仅胚胎暴露的 0.8、2 和 5 ppm 组，即使在 16 周的发育后也是如此。这些结果表明，虽然持续暴露于砷可能会改变肌肉纤维的大小，但仅胚胎暴露于砷对形成的肌肉纤维数量有持久影响。
