低浓度阿维菌素对鲤鱼超氧化物歧化酶(SOD)的影响

Effect of Low Concentration of Avermectins on Superoxide Dismutase (SOD)Activities in Common Carp

研究了阿维菌素长期暴露下鲤鱼肝脏和肌肉超氧化物歧化酶(SOD)活性的动态变化.结果表明:阿维菌素对SOD活性具有较大影响.低浓度组(3.2μg·L-1)SOD活性随暴露时间无显著变化(p>0.05);中浓度组(5.6μg·L-1和7.5μg·L-1)SOD活性先显著上升(p<0.05),随后又显著下降(p<0.05);高浓度组(10μg·L-1和18μg·L-1)SOD活性呈逐渐下降趋势,48h后极显著低于对照(p<0.01).解除污染胁迫10d,低浓度和中浓度组SOD活性能恢复到正常水平,但高浓度组SOD活性不能恢复到正常水平,说明低浓度阿维菌素对鲤鱼机体产生的损伤是可逆性的,而高浓度阿维菌素会对鲤鱼机体产生不可逆损伤.阿维菌素暴露浓度与其对鲤鱼肝脏和肌肉SOD活性抑制率之间具有显著剂量-效应关系,可以考虑将其作为水体中阿维菌素类药物污染的生物标志物;同时,由于正常鲤鱼(对照组)肌肉中SOD活性和受污染胁迫时SOD活性变化的显著性远低于肝脏,因此在考虑用SOD作为生物标志物对水体中阿维菌素污染进行监测时,肝脏是比较理想的取样器官.

The dynamic change of superoxide dismutase（SOD）activity in common carp liver and muscle was studied after the fishes were statically exposed to 3.2, 5.6, 7.5, 10 and 18μg·L-1 Avermectin solution for 20 days. Results indicated that the SOD activity in liver and muscle, at the concentration of 3.2μg·L-1, were not significantly different from the control group （p 0.05）. In 5.6μg·L-1 and 7.5μg·L-1 group, SOD activity increased strongly at first then decreased significantly compared with the control group （p0.05）. In 10μg·L-1 group and 18μg·L-1 group, SOD activity decreased continuously and significantly lower than control （p0.01）after 48h. SOD activity in 3.2, 5.6, 7.2 and 10μg·L-1 groups could return to normal level after 10d recovery, while 18μg·L-1 group could not return to normal level, which showed that low concentration Avermectin might have an reversible damage to carp, while high concentration Avermectin might have an irreversible damage to carp. The significant change of SOD activity in muscle and liver, and the dose-response relationship between Avermectin and SOD activity indicated that the SOD activity of fish was likely to be used as a bio-marker to estimate the biochemical toxicity of Avermectin. Because SOD activity in liver changed much more remarkable than that in muscle after the carps were exposed to Avermectin. As the bio-marker, SOD in liver is better than SOD in muscle.