【摘要】 目的探究日本血吸虫毛蚴感染对湖北钉螺生存及抗氧化酶系统的影响。方法实验组按钉螺与毛蚴数量比为1∶10的比例感染钉螺,同时设对照组(未感染毛蚴的阴性钉螺),各设3组平行。在感染后的0、6、12、24、48、72h和1、2、4、6、8、12周检测钉螺软组织中的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)活性及丙二醛(MDA)的含量,同时记录钉螺存活情况至感染后15周。结果感染毛蚴后,每周实验组钉螺死亡率均高于对照组,至15周时实验组和对照组累计死亡率分别为43.60%和5.93%。钉螺的抗氧化酶活性均呈先上升后下降趋势:SOD活性在24h开始高于对照组,且差异有统计学意义(P<0.05),在第4周达到最大值,第6周开始趋近于对照组水平;CAT和POD活性在72h时开始与对照组差异有统计学意义(P均<0.01),分别于第1周和第2周达到峰值,均于第4周时趋近于对照组水平。实验组MDA含量呈持续升高趋势,与对照组相比,自第2周开始差异有统计学意义(P均<0.01)。结论毛蚴感染能够诱导钉螺产生氧化应激反应,感染早期钉螺能够通过增加体内抗氧化酶活力来缓解毛蚴感染的胁迫压力,但随着时间延长,氧化胁迫逐渐超出机体调节能力,机体出现氧化损伤,并最终导致钉螺死亡。更多还原

【Abstract】 Objective To investigate the effects of Schistosoma japonicum（S.japonicum）infection on the survival rate and the antioxidant enzyme system of Oncomelania hupensis（O.hupensis）.Methods O.hupensis snails were infected with ten-fold S.japonicum miracidium in laboratory setting（experimental group）,and snails without miracidium infection were included as controls.Three replicates were performed for each treatment.The deaths of O.hupensis were continuously recorded till the 15 ^th week following infection,and the activities of superoxide dismutase（SOD）,catalase（CAT）and peroxidase（POD）as well as malondialdehyde（MDA）in the snail were measured at time points of 0,6,12,24 and 48,72 hand week 1,2,4,6,8 and 12,respectively.Results After infection,the weekly mortality of O.hupensis was significantly higher in experimental group than in control group,and the cumulative mortality was 43.6%in the experimental group and 5.93%in the control group by week 15.The activities of antioxidative enzymes initially rose,followed by a reduction in O.hupensis snails.SOD activity appeared higher in the experimental group at 24 hcompared to the control group（P<0.05）,peaked at week 4 and became parallel with levels in control group by week 6.The activity of CAT and POD in experimental group was significantly different from that of the control group at 72 h（both P<0.01）,and peaked at week 1 and week 2,respectively,then arrived at normal level.However,MDA content in the infected O.hupensis snails continued to increase,and was statistically different from that of the un-infected controls since week 2（P<0.01）.Conclusion The infection of S.japonicum can induce oxidative stress in O.hupensis,and the O.hupensis could handle the stress by increasing the activities of antioxidative enzymes at early stage.Nevertheless,oxidative damage would occur in O.hupensis over time once the oxidative stress gradually overwhelmed the regulative capability of O.hupensis itself,eventually leading to the death of O.hupensis snails.更多还原