大鼠松果体囊上皮表面的扫描电镜观察

目的 探讨松果体激素释放到蛛网膜下隙脑脊液途径的结构基础.方法 对1.5月龄和12月龄大鼠松果体浅部,进行松果体囊表面的扫描电镜观察.结果 在大鼠松果体囊表面发现存在筛状囊上皮孔和喇叭口状囊上皮孔.筛状囊上皮孔主要存在于1.5月龄大鼠的松果体囊上皮,是由许多密集排列的囊上皮细胞周边部细胞膜凹陷形成的圆形孔洞,筛孔直径200～500 nm;喇叭口状囊上皮孔见于1.5月龄和12月龄大鼠的松果体囊表面,由相邻上皮细胞向松果体内部凹陷,形成圆形或椭圆形开口,孔径1～4 μm.在两组动物的松果体囊表面,可见到直径800～1 000 nm的球形分泌颗粒样结构.结论 松果体分泌颗粒的释放形式,可能存在连同颗粒被膜的整体释放;松果体激素或分泌颗粒,可能会通过松果体囊上皮孔,直接进入蛛网膜下隙的脑脊液.

A SEM-OBSERVATION ON THE EPITHELIAL SURFACE OF RAT PINEAL CAPSULE

Objective To explore the structural foundation of transport pathway of pineal secretions from the pineal body to the cerebrospinal fluid of subarachnoid space. Methods The pineal capsule of the superficial pineal body of 15-month and 12-month old rats was observed under scanning electron microscope(SEM). Results Cribriform and trumpet-shaped epithelial stomata were scattered on the pineal capsule.Cribriform epithelial stomata were seen mostly in 15-month old rats.They were composed of many round pores which pierced through the full-thickness of the periphery of the capsule endothelium.The pores were dense and ranged from 200-500 nm in diameter;trumpet-shaped epithelial stomata were seen in both 1-5 month and 12-month old rats.Trumpet-shaped epithelial stomata were located among epithelial cells of the pineal capsule.They were round or elliptic in shape and ranged from 1-4 μm in diameter.On the surface of the pineal capsule,many secretory granules were observed.They were spherule and 800 1 000 nm in diameter.Conclusion The releasing pattern of secretory granules of the pineal body could include a releasing of the whole membrane; the pineal secretions may be transported directly from the pineal body to the cerebrospinal fluid of subarachnoid space throu