卫氏并殖吸虫后尾蚴的透射电镜观察

OBSERVATION ON METACERCARIAE OF PARAGONIMUS WESTERMANI BY TRANSMISSION ELECTRON MICROSCOPY

应用透射电镜首次观察了卫氏并殖吸虫后尾蚴的超微结构。虫体由体被、实质组织、肠腔及排泄囊所构成。体被由皮层、肌层、皮层细胞组成。皮层为一合体层,包括外质膜、皮层细胞质和基质膜。皮层表面见许多指状突起,突起有多级分枝。皮层基质内有皮棘,其根部位于基质膜,顶端突出于皮层表面但被外质膜覆盖,横切面上可见网格样结晶,基质内遍布球形、杆状两型分泌小体。皮层细胞位于肌层深部,细胞核位于其内,浆内可见两型特征性分泌小体,皮层细胞发生多条胞质小管穿过肌层及基底膜与皮层相连。结果提示皮层是后尾蚴吸收营养物质的主要部位。

The ultrastructure of metacercariae of Paragonimus westermani was observed by transmission electron microscopy.The worm is composed of integument,parenchyma,gut and excretory sac.The integument consists of tegument,muscular layer and tegumental cell.The tegument,a syncytium,includes tegumental membrane,tegumental cytoplasm,and basal plasma membrane.On the surface of the tegument,many finger-like processes with branches and spines can be readily idendified.The spines projecting beyond the surface of the tegument are completely enclosed within the outer tegument membrane and the basal plasma membrate; in the transverse section,the spine shows a crystalline lattice structure.The tegumental cytoplasm consists of an electron dense granular matrix,in which two types of inclusion bodies,spherical and rod-like bodies may be recognised,both of them comprise a unit membrane and dense granular contents,the rod-like bodies are arranged along the edge of the spines.The tegument nuclei are located not within the surface syncytium but within sunken tegumental cells situated beneath the muscle layer,the tegumental cells contain a few cell organelles,and the two types of characteristic tegument inclusion bodies.The cells are joined to the tegument by one or more long,tortuous cytoplasmic tubules,responsible for the synthesis of the tegumental inclusion bodies,and that these inclusion bcdies are transloested into the tegument by the cytoplasmic tubules.It suggests that the tegument of metacercaria is the main absorptive site of nutrients.