人皮肤内神经-肥大细胞联接在经络线上的发现 Ⅱ“传入性”神经-肥大细胞联接和伴同传出性轴突的薛旺细胞

本研究取材于人的皮肤,电镜常规方法处理。发现人皮肤内有两种类型的神经肥大细胞联接。提示可能分别为传出性和传入性的,或暂称为A型和B型联接,分别报告于上篇和本篇中。 B型联接的构造特点是,脱开薛旺鞘样长带包被的轴突来到肥大细胞近旁,突进细胞体中。轴突终末的一部分被胞质唇封盖起来,终末周围的轴膜与细胞质膜形成联接的双层膜。无肥大细胞表面皱褶参与其形成,无线粒体和显明的囊泡存在终末之内,无薛旺细胞包被轴突终末。薛旺细胞伴同A型联接出现,可与肥大细胞紧密接触。胞质内有狭缝系统和粗面内质网片断,能拖出长尾,估计将过渡为鞘膜。薛旺细胞不是间织细胞,这里的间织细胞应是成纤维细胞。

DISCOVERY OF THE NEUROMASTOCYTIC JUNCTIONS ON THE MERIDIAN LINE IN HUMAN SKIN Ⅱ. THE AFFERENT (?) NEUROMASTOCYTIC JUNCTION AND THE SCHWANN CELLS ACCOMPANYING EFFERENT AXONS

Tissue was removed from human skin on the Foot Yangming meridian line and treated with routine technique used for electron microscopy. Two types of neuromastocytic junction were discovered. They seemed to be of efferent and afferent nature respectiyely in signal transmission and might be tentatively called A-and B-type of junctions. The latter is reported in this paper. Its ultrastructural features are described as follows. The axon became naked near the mast cell and then protruded into the cell body without rupture of its plasma membrane. A part of the axon terminal was covered by the cytoplasmic lips of mast cell so that the axolemma around the terminal came to stand in apposition to the plasma membrane and established the junctional two--layer membrane. No surface folds of mast cell took part in its formation. No mitochondria and vesicles appeared in the terminal. No Schwann cell ensheathed the axon terminal. Schwann cell were found accompanying A-type junction. They envelop- ed the axon terminal and could set up close contact with mast cell.On the other hand they drew off a winding tail, the continuity of which would be Schwann sheath. In cytoplasma, fragments of rough endoplas- mic reticulum and narrow clefts derived from cell surface were regarded as discriminating signs of them. Schwann cell is not interstitial cell that here ought to be fibroblast.