Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP, 18052-780, Sorocaba, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP, 18052-780, Sorocaba, São Paulo, Brazil.
Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP, 18052-780, Sorocaba, São Paulo, Brazil; Programa de Pós-graduação em Biotecnologia e Monitoramento Ambiental, Universidade Federal de São Carlos, Campus Sorocaba, Rodovia João Leme dos Santos, km 110, SP-264, CEP, 18052-780, Sorocaba, São Paulo, Brazil.
Ecotoxicol Environ Saf. 2020 Jun 15;196:110560. doi: 10.1016/j.ecoenv.2020.110560. Epub 2020 Apr 2.
Lithobates catesbeianus tadpoles were exposed to 1 μg L of zinc (Zn), copper (Cu) and cadmium (Cd) alone or combined (1:1 and 1:1:1) for 2 and 16 days. Results showed a significant increase in the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities in the liver, kidney and muscle (except for GPx) in the groups exposed to metal either alone or co-exposed after 2 days compared to the control. After 16 days, SOD, CAT and GST activities decreased significantly in the liver and kidney and GPx activity increased in the liver. Reduced glutathione (GSH) increased in the liver and kidney following combined exposure and decreased after 2 days of metal exposure in the muscle. There were significant increases in lipid hydroperoxide (LPO) levels in the liver, kidney and muscle (2 and 16 days), with the highest levels after metal co-exposure. Cholinesterase (ChE) activity increased significantly in the brain after 2 days of exposure but decreased in the brain (16 days) and muscle (2 days) after exposure to metals, alone and combined. The current study highlighted that the antioxidant system of L. catesbeianus was sensitive to metals and specially to the co-exposure of the three metals, despite presenting differences in the response among tissues. In addition, tadpoles were sensitive at both periods of exposure, but in different modes with stress response (activation, up-regulation) at 2 days and oppression (down-regulation) at 16 days.
牛蛙蝌蚪分别暴露于 1μg/L 的锌（Zn）、铜（Cu）和镉（Cd）单一金属或两两组合（1:1 和 1:1:1）中 2 天和 16 天。结果显示，与对照组相比，暴露于单一金属或联合暴露 2 天后，肝脏、肾脏和肌肉（除 GPx 外）中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）和谷胱甘肽 S-转移酶（GST）的活性均显著升高。16 天后，肝脏和肾脏中的 SOD、CAT 和 GST 活性显著降低，而肝脏中的 GPx 活性增加。联合暴露后，肝脏和肾脏中的还原型谷胱甘肽（GSH）增加，而肌肉中的 GSH 在暴露于金属 2 天后减少。暴露于金属 2 天和 16 天后，肝脏、肾脏和肌肉中的脂质过氧化物（LPO）水平均显著升高，且联合暴露后的 LPO 水平最高。暴露于金属 2 天后，大脑中的胆碱酯酶（ChE）活性显著增加，但暴露于金属 16 天后，大脑和肌肉中的 ChE 活性均降低。本研究表明，尽管不同组织的反应存在差异，但牛蛙蝌蚪的抗氧化系统对金属，特别是三种金属的联合暴露非常敏感。此外，蝌蚪在两个暴露期均敏感，但在不同模式下产生应激反应（激活、上调）和抑制（下调）。
