大白鼠下丘脑促肾上腺皮质激素(ACTH)样免疫反应神经元的分布及功能意义

本文应用免疫细胞化学技术观察大白鼠下丘脑促肾上腺皮质激素样神经元胞体,纤维及串珠样膨体的分布。胞体位于弓状核、下丘脑前核的腹侧、视上背侧连合、室周层的腹侧区及乳头体核腹侧。纤维及串珠样膨体广泛地分布于下丘脑,串珠样膨体在室旁核和室周层密集。串珠样膨体贴室管膜分布,伸至室管膜下神经毯,有的穿行室管膜上皮细胞之间并多与室管膜上皮细胞接触或穿过室管膜上皮细胞之间至第三脑室腔。在第三脑室侧壁的室管膜上皮细胞之间偶见促肾上腺皮质激素反应细胞。室旁核区促肾上腺皮质激素免疫反应串珠样膨体可能作用于催产素和后叶加压素神经元,控制催产素和后叶加压素的分泌和释放。室周层的串珠样膨体直接与脑脊液接触可认为是促肾上腺皮质激素神经元释放分泌产物的另一途径。

LOCALIZATION AND FUNCTIONAL SIGNIFICANCE OF THE IMMUNOREACTIVE NEURONS oF ACTH IN THE HYPOTHALAMUS OF RAT

The localization of immunoreactive cell bodies, fibres and varicosities of ACTH in rat hypothalamus was observed by immunocytochemical method. The immunoreactive cell bodies were located in the arcuate nucleus, the ventral part of the anterior hypothalamic nucleus, the commissura supraoptica dorsalis, the ventral part of periventricular stratum and the ventral part of the mammillary nucleus. The fibres and varicosities were widely distributed over the hypothalamus, but the varicosities were more concentrated in the paraventricular nucleus and periventricular stratum. The varicosities were in close contact with the ependyma of the third ventricle and extended to the underlying neuropil. Some of the varicosities passed through the intercelluar space of ependymal epithelium to get into the cavity of the third ventricle or ia contact with the cells of the ependyma. The immunoreactive cell bodies of ACTH have also been found occasionally between the ependymal epithelial, cells of the lateral wall of third ventricle.The immunoreactive varicosities in the paraventricular area might play role in the control of secretion and release of the vasopressin and oxytocin. The immunoreactive varicosities in the periventricular stratum of the third ventricle in direct contact with the cerebrospinal fluid might be another way of secretion of the ACTH-neurons.