日本血吸虫尾蚴的组织化学及扫描电镜观察

日本血吸虫尾蚴具有一个头腺、2对前钻腺及3对后钻腺,其解剖学位置、构造、化学成分及功能均有区别。钻腺分泌物含有多糖酶及蛋白酶。尾蚴的前端系特化的头器结构,它具有半月形嵴、钻腺开口及乳突。

HISTOCHEMICAL AND SCANNING ELECTRON MICROSCOPICAL OBSERVATIONS ON CERCARIAE OF SCHISTOSOMA JAPONICUM

The chemical nature of the secrections of the glands involved in the penetration process and the surface structure with special reference to penetration of cercariae of Schistosoma japowicum were studied by means of histochemistry and scanning electron microscopy.The glandular system of S. japonicum cercariae consists of three different types of large unicellular glands, namely, one head gland, 2 pairs of pre- and 3 pairs of postr acetabular glands. These glands differ in position, gross feature, histochemistry and functions. As thin starch film and gelatine film substrates were lysed by the living cercariae, both polysaccharase and protease activity were demonstrated in the secretions from the pre- and/or post-acetabular glands of cercariae of S. japonicum.The apex of the head organ form a slightly elevated disc-like area on which are the openings of the pre- and post-acetabular gland ducts. They are linearly arranged into two separate lateral crescents. Each duct opening is encircled by a raised tegumentary folds. There are seven papillae on the convex edge of each crescent. The mouth is situated on mid ventral surface of the head organ and lay within a spineless depression of the tegument. With the exception of the apical region of the head organ of the cer-caria, the whole body surface is covered with backward pointing spines. The spines on the head organ are a little rounder and less spaced than those on the other parts of the body. The number and arrangment of the tegumentary papillae observed by SEM are in accordance with those by acetylthiocholine iodide method, indicating that the aeetylcholinesterase activities are intense in the papillae.