神经垂体内5-羟色胺的免疫电镜研究

本文用免疫电镜方法研究了大鼠神经垂体内5-HT的超微结构分布。结果表明:神经垂体内的5-HT免疫反应产物定位于神经末梢的大颗粒囊泡内、小透亮囊泡表面和线粒体外膜。有时,垂体细胞胞浆也呈5-HT免疫反应阳性。5-HT免疫反应阳性的神经末梢分布于毛细血管周围和垂体细胞附迈。本文首次报道含5-HT的神经末梢可与非5-HT神经末梢形成对称性轴-轴突触。其中,5-HT末梢为突触前成分。本文结果提示:神经垂体内的5-HT不仅可通过非突触方式而且可通过突触方式释放,参与神经内分泌功能的调节。

IMMUNOELECTRON MICROSCOPIC STUDY OF SEROTONIN IN THE NEUROHYPOPHYSIS OF THE RAT

The ultrastructural distribution of serotonin in the neurohypophysis of the rat has heen studied by immunoelectron microscopy. The results showed that the serotonin immunoreactive products of nerve terminals were located in large granular vesicles, around small clear vesicles and at the outer membrane of the mitochondria. Sometimes, the serotonin immunoreactivity was also observed in the cytoplasm of the pituicytes. The serotonin-positive nerve terminals distributed around the capillaries or close to the pituicytes. The present paper reported for the first time that the serotonin-containing nerve terminals formed symmetrical axo-axonic synapses with non-serotoninergic nerve terminals. The results suggested that serotonin in the neurohypophysis could be released not only by non-synaptic but also by synaptic manner to take part in the regulation of neuroendocrine function.