大鼠脑中催产素和加压素免疫反应性物质的分布

用卵白素生物素过氧化物酶复合物(ABC)法研究大鼠脑中催产素(OT)和加压素(VP)免疫反应性物质的分布。阳性细胞主要局限于下丘脑,而阳性纤维则广泛分布于下丘脑和脑干等部位。OT和VP的分布情况有差别。在视上核和室旁核大细胞后部,VP阳性大细胞明显比OT大细胞密集;同样,在向正中隆起方向行走的阳性纤维束中,VP纤维也占大多数。而在室旁核尾部的小细胞内侧部,中小型OT阳性细胞比VP细胞密集;并且,在脑干的孤束核、三叉神经脊束核、迷走背核、疑核、臂旁核和蓝斑核中,OT阳性纤维也占主要地位。 实验结果提示,下丘脑的OT和VP能神经元除参与垂体后叶内分泌外,还可能直接支配一些脑干内脏核。推测在一般正常生理状态下,垂体后叶的VP分泌可能比OT分泌占有更重要的地位;而OT则可能在充当神经递质或调制物,参与下丘脑对脑干内脏核的调节中有更重要的位置。

Distribution of Oxytocin and Vasopressin Immunoreactivity in the Rat Brain

Distribution of oxytocin(OT) and vasopressin(VP) immunoreactivity in the rat brain was studied by avidin-biotin-peroxidase complex(ABC) method. Immunoreactive neurons were primarily present in hypothalamus (HA), while their fibers were dispersed beyoud the HA. There were some differences between the distribution of OT and VP. VP positive magnocells were denser than OT ones in supraoptic nucleus (n.) and the posterior magnocellular part of paraventricular nnc. (PVH). VP fibers were also thicker in the bundle going towards median eminence. On the other hand, the medium and parvus OT neurons in the medial parvocellular part of caudal PVH surpass VP ones in density; OT fibers were also more dominant in solitary n., n. of spinal tract of trigeminal nerve, dorsal motor n. of vagus, ambiguus n., parabrachial n. and locus ceruleus. The results suggested that the OT and VP neurons in HA may directly control various brainstem visceral nuclei as well as participate hypophysial endocrine secretion; the neurohypophysial secretion of VP may be more important than that of OT in common physiological condition, while OT, as a neurotransmitter or modulator, may pay a more prominent role in HA control of brainstem visceral nuclei.