中文摘要：

目的探索湖北钉螺（Oncomelaniahupensis）体内溶菌酶活力与季节变化的关系，及不同螺龄钉螺体内溶菌酶活力差异。方法采用钉螺软体组织匀浆，Tris．HCl．TritonX．114缓冲溶液抽提，经超滤浓缩获得粗制溶菌酶液，BCA法测定蛋白质含量，浊度法测定溶菌酶活力。分析不同季节、不同螺龄钉螺体内溶菌酶活力差异。结果春、夏、秋、冬季钉螺溶菌酶活力分别为（71．33±4．16）、（93．67±7．10）、（150．33±10．01）、（358±35．38）U／mg，冬季活力最高，差异有统计学意义（F=144．455，P〈0．01），成螺和幼螺溶菌酶活力分别为（93．67±7．10）U／mg和（69．33±5．03）U／mg，差异有统计学意义（t=4．845，P〈0．05）。结论湖北钉螺成螺体内溶菌酶活力随季节变化而改变，成螺溶菌酶活力高于幼螺。

英文摘要：

Objective To explore the relationship between the lysozyme activities of Oncomelania hupensis snails among dif- ferent seasons, and the difference of the lysozyme activities among the different ages of the snails. Methods The homogenate soft tissues of O. hupensis were dissolved with Tris-HC1-TritonX- 114 buffer and concentrated, and the enzyme was extracted by centrif- ugation. Results There were significant differences of lysozyme activities among different seasons （Spring, Summer, Autumn, Winter） with the results of 71.33±4.16 U/mg,93.67±7.10 U/mg, 150.33±10.01 U/mg, 358±35.38 U/mg,respectively （F = 144.455, P 〈 0.01 ）. There were also significant differences of the activities between two age groups （adults and young snails） with the re- suits of 93.67±7.10 U/mg and 69.33±5.03 U/mg, respectively （t = 4.845 ,P 〈 0.05）. Conclusion There are significant differenc- es of the lysozyme activities among different seasons and ages of snails, and the highest lysozyme activity is in winter. The lyso- zyme activity of adult snails is higher than that of the youth.