微丝与Sertoli细胞屏障结构关系的研究

STUDIES ON THE STRUCTURAL RELATIONSHIP BETWEEN ACTIN FILAMENTS AND SERTOLI CELL BARRIER

本文应用细胞松弛素E和示踪物镧对微丝在维持Sertoli细胞屏障完整性中的作用进行了形态学研究。结果表明,1.睾丸内注射细胞松弛素E(1000μmol/L)6小时后,可使Sertoli细胞外质特化区(ES)的微丝发生不同程度的破坏,微丝与细胞膜排列关系改变,外质特化区的内质网断裂或消失。随着细胞松弛素E浓度的增加(2000μmol/L)和作用时间的延长(14小时),其变化更趋严重。2.注射细胞松弛素E加高渗右旋醣酐后,构成Sertoli细胞屏障的紧密连接在高渗“应力”作用下被拉开,仅保留间断的点状接触,此时生精上皮基底室和管腔室内的生精细胞皱缩,细胞间隙扩大。3.注入细胞松弛素E后,示踪物镧不仅可进入基底室,而且可深入至管腔室,并围绕在精母细胞与精子细胞周围。说明支持细胞屏障的完整性在细胞松弛素E的作用下受到破坏,特别是支持细胞外质特化区中的微丝破坏甚为关键。本文对微丝与支持细胞屏障的紧密连接的关系及其作用机制进行了讨论。

The present study was designed to investigate the effects of cytochalasin E(CE) on the integrity of Sertoli cell barrier. The results indicate that: (1) In the CE-treated testis(1000-2000 μmol/L CE/testis, 6-14 hr), actin filaments of the ectoplasmic specialization (ES) in area of Sertoli cell barrier were disrupted, the accumulation of amorphous material and fragmented small vesicles of SER were observed in cytoplasm of Sertoli cell. The above changes appeared to be dosage and duration dependent; (2)In the seminiferous tubules of animals receiving CE (1000-2000 μmol/L testis, 6-14 hr) plus fixation with 10% hypertonic dextrose solutions, usually the germ cells shrinkage and exaggeration of intercellular spaces withint he basal as well asthe adluminal compartments were observed. The tight junction between Sertoli cells were also appeared to be separated by hypertonic action of dextros; (3) The results of tracing experiments showed that lanthanums as tracer could be seen to pass through the Sertoli-Sertoli cell junction of the barrier and enter into the adluminal compartment, the tracer that surrounding the spermatocytes and round spermatids were discernible readily. The above results suggest that cytochalsin E disturbed actin filaments of Sertoli ectoplasmic specialization thus altered the functional integrity of the Sertoli cell barrier. The relationship between the actin filaments and Sertoli cell barrier was discussed.