大鼠垂体后叶中神经降压素阳性神经纤维的起源

向垂体后叶注射WGA-HRP,进行逆行追踪并与免疫组织化学相结合研究了大鼠垂体后叶中神经降压素(NT)能神经纤维的起源。投射到垂体后叶的NT免疫阳性神经元胞体主要位于下丘脑室旁核小细胞部、室周区,环状核、室旁核大细胞亚核内侧部、视上核背侧部、穹窿后核及下丘脑前区、外侧区。弓状核内未见任何双标记神经元,从而否定了Goedert等用损毁的方法得出的大鼠垂体后叶中NT阳性神经纤维起源于弓状核的结论。一些室周双标记神经元位于室管膜内,距第三脑室腔很近,常挤在室管膜细胞之间。提示这些神元在监测脑脊液的化学变化,调节垂体后叶分泌方面起一定的作用。

ORIGIN OF NEUROTENSIN IMMUNOREACTIVE NERVE FIBERS IN THE POSTERIOR PITUITARY OF THE RAT

The retrograde tracing technique was combined with immunohistochemical method to study the source of neurotensin positive fibers in the posterior pituitary of the rat. 0.5 or 0.6μl of 3% WGA-HRP(Sigma)were injected into the posterior pituitary of the rat. Retrogradely labeled neurotensin-immunoreactive neurons were found in the parvocellular paraventricular nucleus(PVN), magnocellular PVN, periventricular areas, the dorsal part of supraoptic nucleus, the posterior nucleus of fornix, nucleus circularis, and anterior and lateral area of hypothalamus. No any double labeled neurons was seen in the arcuate nucleus. Our result negated the conclusion on the origin of NT positive nerve fibers in rat neurohypophysis from arcuate nucleus by Goedert et al.