Croteau Maxine C, Martyniuk Christopher J, Trudeau Vance L, Lean David R S
Department of Biology, University of Ottawa, Centre for Advanced Research in Environmental Genomics, Ottawa, Ontario, Canada.
J Toxicol Environ Health A. 2008;71(2):134-44. doi: 10.1080/15287390701613330.
While adverse effects of exposure to ultraviolet B radiation (UVBR) and environmental pollutants on amphibians have been documented, few studies examined the effects of interactions between environmental stressors on amphibian health. Here the impacts of chronic exposure to UVBR and the estrogenic chemical 4-tert-octylphenol (OP), alone and in combination, on the survival, development, growth, and metamorphosis of Rana pipiens (northern leopard frog) tadpoles are evaluated. Tadpoles were exposed to environmentally relevant levels of OP (0.01 or 10 nM), with and without exposure to UVBR (approximately 0.22 W/m2). After 8 mo of exposure, animals were transferred to a clean-water grow-out system for 3 additional mo. There was no effect of treatments on the weights of animals at wk 42 or on the age, snout-vent length (SVL), and weights of tadpoles at forelimb emergence (FLE). However, tadpoles exposed to UVBR had markedly delayed development and significantly fewer reached metamorphosis compared to control animals. Although exposure to UVBR and OP together produced the highest incidence of mortality and developmental anomalies, UVBR alone was sufficient to produce significant mortality of tadpoles, and exposure to UVBR or OP alone induced a significant increase in malformations and abnormalities. The malformations observed consisted mainly of spinal curvature. Our results show that chronic exposure to environmental levels of UVBR or OP alone exerts lethal and/or sublethal effects on R. pipiens tadpoles.
虽然紫外线B辐射（UVBR）和环境污染物对两栖动物的不良影响已有文献记载，但很少有研究考察环境应激源之间的相互作用对两栖动物健康的影响。在此，评估了长期单独或联合暴露于UVBR和雌激素化学物质4-叔辛基苯酚（OP）对北美豹蛙蝌蚪的存活、发育、生长和变态的影响。蝌蚪暴露于环境相关水平的OP（0.01或10 nM），有或没有暴露于UVBR（约0.22 W/m²）。暴露8个月后，将动物转移到清洁水养殖系统中再饲养3个月。处理对42周龄动物的体重或前肢出现时（FLE）蝌蚪的年龄、吻肛长度（SVL）和体重没有影响。然而，与对照动物相比，暴露于UVBR的蝌蚪发育明显延迟，变态的个体显著减少。虽然同时暴露于UVBR和OP导致死亡率和发育异常的发生率最高，但单独UVBR就足以导致蝌蚪显著死亡，单独暴露于UVBR或OP会导致畸形和异常显著增加。观察到的畸形主要是脊柱弯曲。我们的结果表明，长期单独暴露于环境水平的UVBR或OP会对北美豹蛙蝌蚪产生致死和/或亚致死效应。
