大鼠神经垂体内后叶加压素神经分泌末梢的GABA能神经支配的免疫电镜证实  

IMMUNOELECTRON MICROSCOPIC IDENTIFICATION OF GABA-ERGIC INNERVATION OF VASOPRESSIN-NEUROSECRETORY NERVE TERMINALS IN RAT NEUROHYPOPHYSIS

作　　者：朱长庚[1] 张喜京[1] 刘庆莹[1] 蔡秋云[1] 魏瑛[1] 

机构地区：[1]同济医科大学解剖学教研室脑研究室

出　　处：《解剖学报》1994年第3期232-235,T001,共4页Acta Anatomica Sinica

基　　金：国家自然科学基金

摘　　要：为了探讨神经垂体内后叶加压素（ＶＰ）释放的γ－氨基丁酸（ＧＡＢＡ）能神经调控，本研究用包埋前ＡＢＣ法结合免疫电镜双标技术，研究了大鼠神经垂体内ＶＰ能神经和ＧＡＢＡ能神经的超微结构分布及其相互联系。先用ＤＡＢ法显示ＧＡＢＡ免疫反应，然后用钼酸铵－ＴＭＢ法显示ＶＰ免疫反应，再用ＤＡＢ－氯化钴稳定后作免疫电镜包埋。电镜观察发现：在神经垂体内ＧＡＢＡ样免疫反应产物呈电子密度高的颗粒状沉淀，定位于神经末梢内的小清亮羹泡周围和线粒体膜上；ＶＰ样免疫反应产物呈电子密度高的不规则形块状或针状散在于神经分泌末梢内。ＧＡＢＡ样神经末梢分布于神经分泌末梢之间或紧贴毛细血管和垂体细胞，可与神经分泌末梢紧密接触甚至形成突触。ＶＰ样神经分泌末梢内含小透亮囊泡和大颗粒囊泡，并可与ＧＡＢＡ样轴突末梢形成突触。在这种情况下，ＧＡＢＡ样轴突为突触前成分，突触前、后膜呈对称性，突触间隙宽度小于２０ｎｍ，内含电子致密物质。以上结果证实，在大鼠神经垂体内ＶＰ释放受到ＧＡＢＡ神经的直接突触调控。In order to explore the GABA-ergic regulation of VP release in the neurohypophtysis,the ultrastructural distribution of VP-neurosecretory terminals and GABAergic nerves in rat neurohypophysis and their relationship were studied by double lobeling pre embedding immunoelectron microscopic ABC technique,First,the GABA-immunoreaction was demonstrated by chromogen DAB,then the VP immunoreaction was demonstrated by molybdic acid TMB method.After being stabilized by DAB-cobalt chloride,the sections were processed for electron microscopic embedding.Under electron microscope,it was observed that in the neurohypophysis the GABA-LI products appeared as highly electron dense granular deposits located around the small clear vesicles and on the mitochondrial membrane in the nerve endings.Whereas the VP-LI products as highly electron dense irregular masses or needle-like deposits dispersively presented in the axonal terminals.The GABA-LI nerve endings distributed among neurosecretory terminals or close contacted with capillaries,pituicytes,and neurosecretory terminals,including forming synapses with the latter,The VP-LI axonal terminals contained small clear vesicles and large granular vesicles and formed synapses with the GABA-LI axonal terminals,In this case the GABA-LI axonal terminals served as presynaptic elements,the pre-and post-synaptic membrans were symmetrical,the synaptic cleft was less than 2 0 nm in width and contained electron dense materials.The above mentioned results indicated that the VP releasing was directly regulated by GABA-ergic nerves through synaptic contacts.

关 键 词：神经垂体 后叶加压素 氨基丁酸 

分 类 号：R322.81[医药卫生—人体解剖和组织胚胎学]