摘要
通过电镜观察发现：日本血吸虫尾蚴的头腺为多导管的单细胞腺，由腺体部和若干突起状的短导管构成，其分泌小体呈圆形或卵圆形，平均大小为 ０． ２９ × ０． ２３μｍ，具有同心的环层膜状结构。前钻腺含有 Ａ、Ｂ两型分泌小体。 Ａ型分泌小体近似圆形，平均大小为 ０． ４６× ０． ３２μｍ，基质为电子致密的均 匀结构；Ｂ型分泌小体数量众多，略呈不规则的圆形，平均大小为１．０２×０．８２μｍ，基质为中等电子致 密并含十余个小圆形的电子透亮区。后钻腺含有椭圆形或长条状的分泌小体，平均大小为０．９７×０．６２μｍ，基质呈同质性，或伴有电子密度较深的圆形聚集物，或基质呈泡沫状。每根钻腺导管 的胞质外周具有许多沿导管长轴纵行的微管结构，在导管周围有纤维性网状构造包绕，起着对细长导管的支架作用。在导管束外周又有大量肌纤维包统而形成的鞘状结构，它对管内分泌小体的排出可能具有选择性控制作用。
The glandular system of Schistosoma iapoonicum cercariae consists of 3 different types of large unicellular glands, namely, one head gland located in the centre of head organ and 10 glands positioned around the acetabulum. The ten glands are in two sets, each set consisting of two pre-acetabular glands and three post-acetabular glands. The ducts of the glands are joined into two duct bundles which run anteriorly and become narrow. Each bundle of five ducts is encompassed by two layers of muscle. The extracellular space between the gland ducts is filled with an extracellular fibrous net work and microtubules line the inner-side of the duct membrane. The most abundant cytoplasmic inclusions of the post-acetabular glands are the secreto- ry globules. Each globule is elongate oval or irregular in shape averages about 0. 97 × 0. 62 μm. The globule matrix consists of a finely granular, homogeneous ground substance in which is embedded round, electron dense aggregates measuring about 0.2 μm in diameter. As the secretory globules move form the fundus through the duct, they become more homo-geneous and the electron dense aggregates decrease progressively. Apart from the secretory globules, small mitochondria, electon dense granules (probably granules of glycogen) occur in the cytoplasm of the post-acetabular glands. In the pre-acctabular glands there are two morphologically distinct types of secretory globules. On type (type A) is electron dense showing oval in shape, measuring 0.46 × 0.32 μm in size. The second type (type B) of secretory globules is more abundant than type A, and measure about 1. 02 × 0. 82 μm in size. The type B globules have a matrix of medium electron density, and within the matrix are numerous small circular electron lucid areas, about 0.12 μm in diameter; a thin network of anastomosing components can be seen within the lucid areas. Changes in the appearnce of the type B globules occur as they move toward the distal part of the duct , and the electron lucid areas become fewer. As they move toward the duct opening, the globules are mostly of a homogeneous nature. The head gland consists of a fundus and multiple ducts that open into the surface at the anterior end of the head organ. The fundus contains most of the secretory globules which are concentric with multilamellated membranes like finger print. Each globule is round or oval in shape and averages about 0.29 × 0. 23 μm.
出处
《动物学报》
SCIE
CAS
CSCD
1994年第2期113-118,共6页
ACTA ZOOLOGICA SINICA
关键词
日本血吸虫
尾蚴
头腺
钻腺
结构
Schistosoma japonicum, Cercaria, Head gland, Acetabular glands, Ultrastructure.
