【摘要】 目的观察空心莲子草抑制钉螺运动及灭螺的机制。方法将实验钉螺随机分为4组,分别于空心莲子草浸液(1g/L)及去氯水中各浸泡12h和20h后,用酶组织化学方法染色,显微镜下观察钉螺的头足部、中枢神经节、鳃叶及肝脏的三磷酸腺苷酶(Mg2+-ATPase)、胆碱脂酶(ChE)、乳酸脱氢酶(LDH)和琥珀酸脱氢酶(SDH)的活性;并用计算机图像分析系统(HPIAS-1000)检测各组不同部位染色片的灰度值,进行定量分析。结果空心莲子草浸液12h和20h组,在钉螺头足部、中枢神经节及鳃部的ChE酶染色均明显变淡,显示该酶的活性减弱。图像分析系统检测各组不同部位染色片的灰度值,结果显示,空心莲子草浸液12h和20h组ChE活性在头足部(130.95±8.08,129.91±7.05)、中枢神经节(127.43±7.27,126.78±7.38)和鳃叶(121.38±7.31,126.41±8.28)与对照组的相应部位(分别为64.65±8.54、65.18±7.96,57.86±6.57、50.71±6.15,88.96±6.78、89.86±7.01)比较,差异均有统计学意义(P<0.01)。空心莲子草浸液20h组钉螺的Mg2+-ATPase活性在头足部(89.91±5.08)、中枢神经节(71.15±5.43)及肝脏(112.40±7.81)与对照组(分别为78.81±8.10、60.09±6.05和95.50±8.35)比较,差异有统计学意义(P<0.05),但浸泡12h组的Mg2+-ATPase活性与对照组比较,差异无统计学意义(P>0.05)。空心莲子草浸液12h和20h组的LDH和SDH活性与对照组的比较,差异均无统计学意义(P>0.05)。结论空心莲子草浸液主要通过迅速抑制钉螺体内ChE活性,随后抑制Mg2+-ATPase活性,而导致ATP的释放与利用障碍致钉螺死亡。更多还原

【Abstract】 Objective To investigate the mechanisms of Alternanthera philoxeroides(Mardus) Grisebach in inhibiting Oncomelania snails’ locomotivity and killing effect.Methods Uninfected snails were divided into four groups and exposed to an aqueous extract of A.philoxeroides and dechlorinated water(as control) for 12 h or 20 h,respectively.The activities of the Mg2+-adenosine triphosphatase(Mg2+-ATPase),cholinesterase(ChE),lactate dehydrogenase(LDH) and succinate dehydrogenase(SDH) in the head-foot muscles,centric ganglions,gills and liver of Oncomelania hupensis were analyzed using enzyme histochemistry technology and changes were observed under a light microscope.Statistical quantitative analysis of data of grey values was conducted on the computer-assisted image analyzing system(HPIAS-1000).Results The color of stained ChE in the head-foot muscles,centric ganglions and gills of the snail lightened evidently,showing a decrease of ChE activity after snails were immersed in the extract of A.philoxeroides for 12 h or 20 h.Results of grey values at different stained parts of snail,measured by the computer-assisted image analyzing system,indicated that there was a significant difference(P <0.01) between the activities of ChE in the head-foot muscles(130.95±8.08,129.91±7.05),centric ganglions(127.43±7.27,126.78±7.38) and gills(121.38±7.31,126.41±8.28) from snails exposed to aqueous extract of A.philoxeroides for 12 h and 20 h and the activities of the enzyme in counter-parts(64.65±8.54,65.18±7.96,57.86±6.57,50.71±6.15,88.96±6.78 and 89.86±7.01,respectively) from control group.The activities of Mg2+-ATPase also showed a significant difference(P<0.05) in the head-foot muscles(89.91±5.08),centric ganglions(71.15±5.43) and liver(112.40±7.81) of the snail after 20 h of exposure against those in counter-parts(78.81±8.10,60.09±6.05 and 95.50±8.35,respectively) from the control,but no significant difference(P>0.05) was shown on the activities of Mg2+-ATPase between the snails exposed for 12 h in extract of A.philoxeroides and those of control.No statistical difference(P>0.05) was found between the dechlorinated water group and the extract of A.philoxeroides group in the activities of LDH and SDH after 12 h or 20 h of exposure.Conclusion The extract of A.philoxeroides rapidly inhibits ChE,and then the activity of Mg2+-ATPase,which may suppress the release and utilization of ATP in the Oncomelania snails and finally causes death of snails.更多还原