Behavioral changes in female Swiss mice exposed to tannery effluents

Abstract Among the anthropic activities generating potentially toxic residues are those involved with bovine hide processing (tannery industries). However, knowledge is scant regarding the damage caused to the health of various organisms by tannery waste and studies are rare, especially in mammalian experimental models. This study therefore aimed to evaluate the physical and behavioral effects of the exposure of female Swiss mice to tannery effluent. To accomplish this, for a period of 15 days the animals were fed tannery effluent diluted with water in the following concentrations: 0% (control group, received only potable water), 5% and 10%. The body mass of the animals was evaluated at the beginning and end of the experiment, as well as the daily consumption of water and food. After 15 days of exposure to the effluent, the animals were submitted to the elevated plus maze (predictive of anxiety) and the forced swim test (predictive of depression). The treatments did not affect the animals' body mass, either in eating behavior or in consumption of water. However, it was found that the animals that ingested tannery effluent concentrations of 5% and 10% exhibited an anxiolytic (lower level of anxiety, greater percentage of time in the open arms, longer time and frequency in the diving behavior, less time of lurks and less frequency of freezing) and an antidepressant effect (more time in climbing behavior and less time of immobility) when compared to the control group. It was concluded that the exposure of female Swiss mice to tannery effluents (5% and 10% diluted with water) causes behavioral changes, possibly related to the neurotoxicity of this waste, without causing physical changes in the animals.

摘要：在可产生潜在有毒残留的人类活动中，涉及牛皮加工的制革工业位列其中。目前学界对制革废弃物对多种生物体健康造成的损害认知匮乏，相关研究尤为稀缺，尤其是在哺乳动物实验模型领域。因此本研究旨在探究雌性瑞士小鼠接触制革废水（tannery effluent）所产生的生理与行为学效应。为实现该研究目的，实验周期为15天，受试小鼠饮用经自来水稀释的不同浓度制革废水：浓度分别为0%（对照组，仅饮用饮用水）、5%与10%。分别于实验开始与结束时测量小鼠的体质量，并记录其每日饮水与进食量。在暴露于废水15天后，对受试小鼠开展高架十字迷宫（elevated plus maze，焦虑评价模型）实验与强迫游泳（forced swim test，抑郁评价模型）实验。各实验组对小鼠的体质量、进食行为及饮水消耗量均无显著影响。然而与对照组相比，摄入5%与10%浓度制革废水的小鼠表现出抗焦虑样效应（焦虑水平降低、开放臂停留时间占比升高、潜水行为时长与频率增加、潜伏时长缩短以及僵立行为频率降低）以及抗抑郁样效应（攀爬行为时长增加、静止不动时长减少）。综上，雌性瑞士小鼠饮用经自来水稀释的5%与10%浓度制革废水可引发行为学改变，该效应可能与该废弃物的神经毒性相关，但不会对小鼠的生理状态造成影响。