大鼠神经垂体催产素能神经元内神经分泌颗粒的免疫电镜观察

IMMUNOELECTRON MICROSCOPIC OBSERVATION FOR NEUROSECRETORY GRANULES OF OXYTOCINERGIC FIBER IN NEUROLOBE OF RAT HYPOPHYSIS

目的 观察大鼠神经垂体催产素（ＯＴ）能神经元轴突及终末内颗粒囊泡形态学及免疫细胞化学特点。方法 应用电镜包埋后免疫细胞化学方法，对大鼠神经垂体进行ＯＴ免疫染色。结果 在ＯＴ能神经元轴突终末内，可见ＯＴ免疫反应性的致密核芯大颗粒囊泡和无ＯＴ免疫反应性的清亮小泡存在。部分囊泡与轴膜靠近，并可见颗粒囊泡与轴膜融合形成的胞吐现象；在轴突非终末部分，也可见ＯＴ免疫反应性的颗粒囊泡，散在分布轴浆内，还可见无ＯＴ免疫反应性的颗粒囊泡，呈散在或聚集分布，两种囊泡均可位于微管之间。结论 位于轴突和轴突终末内的囊泡，在形态学和ＯＴ免疫染色方面有明显差异，推测它们在功能上也有不同。

Objective\ To observe the morphological and immunocytochemical characteristic of the secretory granules within the axon and axonal terminal of oxytocinergic neurons.Methods\ Postembedding immunocytochemistry for electron microscopy was used for labelling oxytocinergic neurofiber in neurolobe of rat hypophysis.Results\ The large dense core granules with oxytocin(OT) immunoreactivity and clear microvisicles without OT immunoreactivity were observed in the axonal terminal of the neuron.Some OT positive granules were fused with the membrane of the terminal and exocytosis of the granules were demonstrated.In the rest part of axon,the scattered or packaged granules without OT immunoreactivity and scattered granules with OT immunoreactivity were found to be located at the space between microtubes of the axon.Conclusions\ Because there are some morphological and immunocytochemical difference between the granules in axon and axonal terminal,there might be some functional difference between them.\;