铅对河南华溪蟹卵巢抗氧化酶活力和脂质过氧化水平的影响

Effects of lead on ovaries lipid peroxidation level and antioxidant enzyme activity in freshwater crab Sinopotamon henanense

采用亚急性毒性实验方法,研究了铅(Pb2+)对河南华溪蟹(Sinopotamon henanense)卵巢组织抗氧化酶活性与脂质过氧化产物的影响.实验设置了5个Pb2+浓度组(3.675、7.35、14.70、29.40和58.80mg·L-1)和1个空白对照组,在3个染毒时间(5、10和15d)下对超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GPx)活力和丙二醛(MDA)含量进行了测定.结果显示,在不同浓度和不同暴露时间下,铅对河南华溪蟹卵巢SOD、CAT、GPx活力及MDA含量均有明显的影响.SOD、CAT活力表现为低浓度诱导激活,高浓度抑制,即先升后降的变化规律,GPx活力在5d和10d时表现出先升后降的趋势,在15d时活力不断下降,且SOD在10d、14.70mg·L-1Pb2+浓度组,CAT在5d、7.35mg·L-1Pb2+浓度组,GPx在10d、3.675mg·L-1Pb2+浓度组分别升至峰值,而卵巢MDA含量随染毒时间的延长和染毒浓度的升高逐渐增多,且在15d、58.80mg·L-1Pb2+浓度组中较对照组差异极显著。结果表明,Pb2+暴露对河南华溪蟹卵巢产生了明显的氧化胁迫作用,且抗氧化酶和脂质过氧化物水平可以作为重金属对水生生物毒理学研究的生物标志物.

To explore the effects of lead（Pb2＋） on the ovary,the freshwater crabs,Sinopotamon henanense,were exposed to 0,3.675,7.35,14.70,29.40,and 58.80 mg · L-1 Pb2＋ for 5,10 and 15 d.The activities of antioxidant enzymes,including superoxide dismutase（SOD）,catalase（CAT）,and glutathione peroxidase（GPx）,and the contents of malondialdehyde（MDA） in ovarian tissues were investigated.The results showed that Pb2＋ significantly impacted the activities of SOD,CAT and GPx and altered the contents of MDA in the ovary.MDA content was found to increase persistently during Pb2＋ exposure,with the maximum level,occurring at day 15 in crabs exposed to 58.80 mg · L-1 Pb2＋.Low concentrations of Pb2＋ were found to stimulate the activities of the three antioxidant enzymes.SOD activity peaked at day 10 in crabs exposed to 14.70 mg · L-1 Pb2＋,while CAT activity reached the peak after a 5-day exposure to 7.35 mg · L-1 Pb2＋ and GPx activity from crabs exposed to 3.675 mg · L-1 Pb2＋ rose to the highest at day 10.However,for crabs exposed to high concentrations of Pb2＋,the activities of the three antioxidant enzymes were all inhibited with prolonged exposure time.The significant buildup of MDA in ovarian tissues following Pb2＋ exposure is indicative of Pb2＋-induced oxidative damages to crab ovary.Because the increase in ovarian MDA was persistent during Pb2＋ exposure,this biochemical parameter can be used as a biomarker for heavy metal-induced oxidative damages to aquatic animals.