Effects of glyphosate and the glyphosate based herbicides Roundup Original(®) and Roundup Transorb(®) on respiratory morphophysiology of bullfrog tadpoles.
Effects of glyphosate and the glyphosate based herbicides Roundup Original(®) and Roundup Transorb(®) on respiratory morphophysiology of bullfrog tadpoles.
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DOI：
10.1016/j.chemosphere.2016.04.083
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发表时间：
2016-08
期刊：
影响因子：
8.8
通讯作者：
R. Z. Rissoli;F. Abdalla;M. J. Costa;F. Rantin;D. McKenzie;A. Kalinin
中科院分区：
文献类型：
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作者：
R. Z. Rissoli;F. Abdalla;M. J. Costa;F. Rantin;D. McKenzie;A. Kalinin
草甘膦除草剂广泛用于农业，通常存在于水体中。Roundup Original®（RO）含有含有表面活性剂POEA的异丙胺草甘膦（GLY）盐，而Roundup Transorb R®（RTR）含有GLY与未知表面活性剂的钾盐。两者都含有所谓的“惰性”成分的不同成分，比草甘膦毒性更大。两栖类蝌蚪在其水生栖息地中经常经历氧气供应的变化;耐受缺氧的能力可以决定它们的生存和健康。我们评估了亚致死浓度的GLY（1 mg L− 1）、RO（1 mg L− 1 GLY ae）和RTR（1 mg L− 1 GLY ae）对牛蛙蝌蚪在常氧和分级缺氧条件下代谢率（V·O2-mLO 2 Kg 1 h− 1）的影响，并将其与皮肤形态学（主要气体交换部位）联系起来。在对照组（CT）中，V·O2从常氧到40 mmHg保持不变，表明临界O2张力在40 ~ 20 mmHg之间。GLY显著降低V·O2，可能是由于表皮肥大，增加了O2扩散到O2摄取的距离。相反，RTR增加缺氧时的V·O2，表明“惰性”化合物和表面活性剂的影响。RO的V·O2与CT无差异，表明暴露引起的任何V·O2增加都被表皮肥大所拮抗。事实上，所有除草剂引起皮肤形态的显着改变，细胞和上皮细胞壁呈现增生或肥大和染色单体断裂。总之，GLY、RO和RTR在牛蛙蝌蚪中发挥不同的作用，特别是表面活性剂和惰性化合物似乎影响氧摄取。
Glyphosate-based herbicides are widely used in agriculture and are commonly found in water bodies. Roundup Original®(RO) contains an isopropylamine glyphosate (GLY) salt containing the surfactant POEA, while Roundup Transorb R®(RTR) contains a potassium salt of GLY with unknown surfactants. Both contain different compositions of so-called “inert” ingredients, more toxic than glyphosate. Amphibian tadpoles often experience variations in O 2 availability in their aquatic habitats; an ability to tolerate hypoxia can condition their survival and fitness. We evaluated the impacts of sublethal concentrations of GLY (1 mg L− 1), RO (1 mg L− 1 GLY ae) and RTR (1 mg L− 1 GLY ae) on metabolic rate (V· O 2–mLO 2 Kg1 h− 1) of bullfrog tadpoles during normoxia and graded hypoxia, and related this to morphology of their skin, their major site of gas exchange. In control (CT) V· O 2 remained unaltered from normoxia until 40 mmHg, indicating a critical O 2 tension between 40 and 20 mmHg. GLY significantly reduced V· O 2, possibly due to epidermal hypertrophy, which increased O 2 diffusion distance to O 2 uptake. In contrast, RTR increased V· O 2 during hypoxia, indicating an influence of “inert” compounds and surfactants. V· O 2 of RO did not differ from CT, suggesting that any increase in V· O 2 caused by exposure was antagonized by epidermal hypertrophy. Indeed, all herbicides caused marked alterations in skin morphology, with cell and epithelium wall presenting hyperplasia or hypertrophy and chromatid rupture. In summary, GLY, RO and RTR exert different effects in bullfrog tadpoles, in particular the surfactants and inert compounds appear to influence oxygen uptake.