Sitzlar M A, Mora M A, Fleming J G W, Bazer F W, Bickham J W, Matson C W
Department of Wildlife and Fisheries Sciences, Texas A&M University, 2258 TAMU, College Station, TX 77843-2258, USA.
Ecotoxicology. 2009 Jan;18(1):15-21. doi: 10.1007/s10646-008-0251-8. Epub 2008 Aug 1.
Cliff swallows (Petrochelidon pyrrhonota) and cave swallows (P. fulva) were sampled during the breeding season at several locations in the Rio Grande, Texas, to evaluate the potential effects of environmental contaminants on P450 aromatase activity in brain and gonads and DNA damage in blood cells. The tritiated water-release aromatase assay was used to measure aromatase activity and flow cytometry was used to measure DNA damage in nucleated blood cells. There were no significant differences in brain and gonadal aromatase activities or in estimates of DNA damage (HPCV values) among cave swallow colonies from the Lower Rio Grande Valley (LRGV) and Somerville. However, both brain and gonadal aromatase activities were significantly higher (P < 0.05) in male cliff swallows from Laredo than in those from Somerville. Also, DNA damage estimates were significantly higher (P < 0.05) in cliff swallows (males and females combined) from Laredo than in those from Somerville. Contaminants of current high use in the LRGV, such as atrazine, and some of the highly persistent organochlorines, such as toxaphene and DDE, could be potentially associated with modulation of aromatase activity in avian tissues. Previous studies have indicated possible DNA damage in cliff swallows. We did not observe any differences in aromatase activity or DNA damage in cave swallows that could be associated with contaminant exposure. Also, the differences in aromatase activity and DNA damage between male cliff swallows from Laredo and Somerville could not be explained by contaminants measured at each site in previous studies. Our study provides baseline information on brain and gonadal aromatase activity in swallows that could be useful in future studies.
在繁殖季节，于得克萨斯州格兰德河的多个地点采集了崖燕（Petrochelidon pyrrhonota）和洞燕（P. fulva）样本，以评估环境污染物对大脑和性腺中P450芳香化酶活性以及血细胞DNA损伤的潜在影响。采用氚标记水释放芳香化酶测定法测量芳香化酶活性，并用流式细胞术测量有核血细胞中的DNA损伤。下格兰德河谷（LRGV）和萨默维尔的洞燕群体在大脑和性腺芳香化酶活性或DNA损伤估计值（HPCV值）方面没有显著差异。然而，拉雷多的雄性崖燕大脑和性腺芳香化酶活性均显著高于（P < 0.05）萨默维尔的雄性崖燕。此外，拉雷多的崖燕（雄性和雌性合计）的DNA损伤估计值显著高于（P < 0.05）萨默维尔的崖燕。LRGV当前高用量的污染物，如阿特拉津，以及一些高持久性有机氯，如毒杀芬和滴滴涕，可能与禽类组织中芳香化酶活性的调节有关。先前的研究表明崖燕可能存在DNA损伤。我们未观察到洞燕的芳香化酶活性或DNA损伤有任何与污染物暴露相关的差异。此外，拉雷多和萨默维尔的雄性崖燕之间芳香化酶活性和DNA损伤的差异无法用先前研究中在每个地点测量的污染物来解释。我们的研究提供了关于燕子大脑和性腺芳香化酶活性的基线信息，这可能对未来研究有用。
