中文摘要：

目的湖北钉螺（0．hupensis）的内在防御机制，特别是它们的血淋巴细胞，被认为是无脊椎动物防御系统的主要效应因子，对于控制寄生虫病的传播很有意义。在本次实验中，我们对于阴性湖北钉螺（0．hupensis）和感染日本血吸虫（Schistosoma japonicum）的阳性湖北钉螺（0．hupensis）的血淋巴细胞进行了定性和定量的比较研究。方法分别在培养后3、5、7、12、16、20、25、30、35、40、45、50、55、60、65、70、75、80、85和90d对其进行连续组织切片和H＆E染色观察。结果发现血淋巴细胞具有一个圆形的核，在其被染成深蓝色的细胞质中有一些密集的颗粒状物质。根据细胞核的体积，血淋巴细胞可以分为大、中和小3种娄型，其直径分别为8．1～8．6μm（大），5．5～6．0μm（中），4．2～4．7μm（小）。通过对湖北钉螺（0．hupensis）的足部、围心腔、胃肠道、消化腺以及生殖腺5个器官部位的血淋巴细胞计数观察发现感染日本血吸虫（S．japonicum）后的湖北钉螺（0．hupensis），这几处的血淋巴细胞数量都有所增加。湖北钉螺的血淋巴细胞在围心腔处最多，而在足部区域最少。这3种类型的血淋巴细胞在钉螺所有部位都有所增加，且中型血淋巴细胞最多，大型和小型血淋巴细胞较少。结论本次研究中所得到的数据在湖北钉螺（0．hupensis）对于日本血吸虫（S．japonicum）的内在防御机制以及更有效的控制血吸虫病的深入研究中具有相当的意义。日本血吸虫；湖北钉螺；血淋巴细胞；分布

英文摘要：

Knowledge of defense mechanism of O. hupensis, particularly their haemo-lymphocytes, which are considered to be the main effectors of invertebrate defense system, should be beneficial to control the disease transmission. In this study, qualitative and quantitative investigations of haemo lymphocytes in negative and positive O. hupensis after infection with S. ja- ponicum was conducted by histological sectioning of infected snails at post-infection days 3, 5, 7, 12, 16, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, and 90. H＆E stained haemo lymphocytes had an appearance with circular nucleus and densely packed granules inside the cell with entire cytoplasm stained deep blue in color. The haemo lymphocytes were divided into three types based on their nucleus sizes： large, medium, and small, with diameter ranges of 8. 1 8.6 /μm （large）, 5.5 6.0 /μm （medium）, and 4.2-4.7 μm （small）. Post-infection increase in numbers of haemo lymphocytes in five organs of infec- ted snails including foot, pericardial, gastrointestinal, alimentary gland, and genital organs regions was observed. The rich are- a of haemo lymphocytes was in the pericardial region. Moreover, the fewest number of haemo lymphocytes presented in foot region. The numbers of haemo-lymphocytes with three nucleus sizes in all snail body parts were clearly increased at beginning, then slightly decreased later, and the haemo lymphocytes with medium nucleus size was the dominated population. The haemo lymphocytes with large and small nucleus sizes were found but few in number, Data gathered during the present study should be useful in understanding the defense mechanism of O. hupensis in response to S. japonicum infection, and further the re search with the aim of controlling the disease more effectively.