ABSTRACT
To investigate the function of microtubules (MTs) in Sertoli cell, colchicine, a microtubule disrupting agents, was injected into the dorsum of the male SD rat. The seminiferous tubules and Sertoli cell of the rat were examined by light and electron microsopy. 5-6 hours after the colchicine injection the following results were revealed (1) The Sertoli cell of the rat testis showed prominent morphological changes. The processes of the cell retracted, the MTs disappeared in the cytoplasm and the distribution of mitochondria and smooth endoplasmic reticulum became irregular. (2) Many widened intercellulor spaces occured in the seminiferous epithelium; and accordingly the arrangement of the germ cells became deranged and the elongated spermatids moved form their original deep position to the surface of the epithelium. (3) There was no evident changes in the basal region of the seminiferous epithilium. These results confirmed that MTs in Sertoli cell are essential to the maintenance of the normal shape and cellular organelle arrangement in the cell as well as the architecture of seminiferous epithelium. They may also play an important role in the movement of the elongated spermatids.
ABSTRACT
The postnatal development of the ectoplasmic specialization (ES) of Sertoli cells was investigated in the rats from 1st to 8th week after birth and the adult by electron microscopy. At the end of the 1st week. ES is in the beginning of its formation. Some high electron dense materials accumulate in the submembranous regions and short cisternae of endoplasmic reticulum align in these zones. At the end of the 2nd week the short cisternae are fused each other and straight microfilaments bundles appear and are sandwiched between the flattened cisternae and cell membrane. The density of microfilaments is increased in the 3th week and numerous tight junctions appear between adjacent Sertoli cells. The ES is gradually completed in its structure until the 5th week and fully extend and circumscribed around the base of Sertoli cells. Thereafter, there is no more morphological changes. We conclude that the first 5 weeks after birth is the important period for the development of ES of Sertoli cell as well as the blood-testis barrier in rats.
ABSTRACT
The distribution of microtubules (MTs)in the Sertoli cell of rat testis was studied with indirect immunofluorescence and electron microscopy. We have found that MTs are mainly located in the cytoplasm apical to the nucleus and oriented parallel to the long axis of the Sertoli cell. MTs may extend into the stalks and processes of the cell which embrace different germ cells. With the changes of the architecture of the seminiferous epithelium and the shape of Sertoli cells, there are some regular changes in MTs distribution during the seminifeous epithelium cycle. In stage Ⅰ-Ⅴ, many MTs aggregate around the elongated spermatids and are parallel to their long axis. During stage Ⅶ maturing spermatids are suspended into the lumen by the Sertoli cell processes containing numerous MTs. Some of the MTs conform to the contour of the hook-shaped spermatids heads. After spermiation (stage Ⅶ-Ⅸ), MTs retract from the lumen with the Sertoli cell processes and gather around the spermatids which just start their elongation. These results indicate that the distribution of the MTs in Sertoli cell has close relations with the architecture of the seminiferous epithelium, and the changes of the Sertoli cell shape and the movement of the spermatids.