[Distribution of microfilaments in rat Sertoli cells in vivo and in vitro].

The distribution of microfilaments (MFs) in rat Sertoli cells in vivo and in vitro was studied with electron microscopy and the TRITC-phalloidin staining method. The results revealed the following: The MFs of the Sertoli cells in vivo are arranged in bundles just beneath the cell membrane. MF bundles may form a band-like structure circumscribing the basal region of each Sertoli cell. The filaments and bundles are parallel with each other and their arrangement is symmetrical on the opposite sides of two adjacent Sertoli cell membranes. In vitro, the arrangement and distribution of MF bundles are closely related with the living and spreading state of the cell. In a fully spread cell, MFs bundles are arranged in parallel just beneath the cell membrane. We conclude that MFs in rat Sertoli cells are mainly arranged in bundles and stretched beneath the cell membrane. They may play an important role in maintaining the shape of the cell and the blood-testis barrier.