de Paiva Paula Pereira, Delcorso Mariana Cruz, Matheus Valquíria Aparecida, de Queiroz Sonia Claudia do Nascimento, Collares-Buzato Carla Beatriz, Arana Sarah
Department of Biochemistry and Tissue Biology, University of Campinas (UNICAMP), Po. Box 6109, 13083-970, Campinas, SP, Brazil.
Laboratory of Residues and Contaminants, Embrapa Environment, Jaguariúna, SP, Brazil.
Vet World. 2017 Sep;10(9):1008-1019. doi: 10.14202/vetworld.2017.1008-1019. Epub 2017 Sep 1.
The aim of this work was to evaluate the sensitivity of Pacu fingerlings () by measuring the effects of median lethal concentration (LC) of atrazine (ATZ - 28.58 mg/L) after acute exposure (up to 96 h).
The fish were exposed to the LC of ATZ for 96 h (28.58 mg/L) in a static system. During the experiment, the fingerlings were randomly distributed in four glass tanks (50 L) containing dechlorinated water. Four glass tanks were for the control group, and four were for the ATZ-exposed group (n=4 per glass tank), given a total number of 16 animals tested per group. The genotoxicity was evaluated by micronucleus (MN) test in erythrocytes from peripheral blood. Qualitative and semi-quantitative histopathological analyses, and also ultrastructural study, were applied in liver and kidney samples. Finally, the content of heat shock protein (Hsp70) in the liver was evaluated by the western blotting method.
The morphological alterations in the liver, which was associated with increased expression of Hsp70, included nuclear and cytoplasmic vacuolization, cytoplasmic hyaline inclusions, and necrosis. The kidney presented edema and tubular cell degeneration with cytoplasmic hyaline inclusion. The semi-quantitative histopathological analyses indicated that the liver was more sensitive than kidney to ATZ-induced damage. Ultrastructural analysis showed that ATZ caused membrane alterations in several organelles and increased the number of lysosomes in hepatocytes and kidney proximal tubular cells. Nevertheless, no significant difference was observed in MN frequency in erythrocytes comparing treated and control groups.
These results indicated that ATZ-induced damage to the kidney and liver function, ATZ at the concentration tested did not induce a significant difference in MN frequency in Pacu erythrocytes comparing treated and control groups, and also that Pacu fingerlings may be a good bioindicator for testing freshwater contamination.
本研究旨在通过测定急性暴露（长达96小时）后莠去津（ATZ - 28.58毫克/升）的半数致死浓度（LC）的影响，评估淡水白鲳幼鱼的敏感性。
将鱼在静态系统中暴露于ATZ的LC浓度（28.58毫克/升）下96小时。实验期间，幼鱼随机分布于四个装有去氯水的玻璃水箱（50升）中。四个玻璃水箱作为对照组，四个作为ATZ暴露组（每个玻璃水箱n = 4），每组共测试16只动物。通过外周血红细胞微核（MN）试验评估遗传毒性。对肝脏和肾脏样本进行定性和半定量组织病理学分析以及超微结构研究。最后，通过蛋白质免疫印迹法评估肝脏中热休克蛋白（Hsp70）的含量。
肝脏的形态学改变包括核空泡化、细胞质空泡化、细胞质透明包涵体和坏死，这些改变与Hsp70表达增加有关。肾脏出现水肿和肾小管细胞变性以及细胞质透明包涵体。半定量组织病理学分析表明，肝脏比肾脏对ATZ诱导的损伤更敏感。超微结构分析显示，ATZ导致多个细胞器的膜改变，并增加了肝细胞和肾近端小管细胞中溶酶体的数量。然而，比较处理组和对照组，红细胞中的MN频率没有观察到显著差异。
这些结果表明，ATZ对肾脏和肝脏功能造成损伤，在所测试的浓度下，ATZ在处理组和对照组的淡水白鲳红细胞中未诱导MN频率出现显著差异，并且淡水白鲳幼鱼可能是测试淡水污染的良好生物指示物。
