腺垂体结构特点及其与蛛网膜下隙关系的形态学研究

发布时间：2018-05-08 04:37

本文选题：腺垂体 + 细胞间池　；参考：《河北医科大学》2007年硕士论文

【摘要】： 垂体是机体重要的内分泌器官,从胚胎发生学和组织学特点,可分为腺垂体和神经垂体两部分,产生多种肽类激素。近年来,关于垂体的研究仍存在一些有争议的问题。第一,关于垂体周围是否也存在脑组织表面的三层被膜,仍有不同的说法,有学者认为垂体外面包以由硬膜构成的被囊,在鞍隔以下,垂体周围没有蛛网膜和软脑膜,硬脑膜与垂体紧密相贴。也有学者认为,由于多数鞍隔孔的边缘离垂体柄较远,鞍隔以上的蛛网膜,在垂体柄处反折,约有8%~56%的个体,其蛛网膜突入孔内,深度多2mm。还有人认为,蛛网膜可经鞍膈孔突入鞍内,形成垂体周围的蛛网膜下隙。Kaufman根据蝶鞍影像学表现认为,垂体周围存在蛛网膜囊。第二,关于腺垂体多肽激素的释放形式和转运途径,多数学者认为,腺垂体多肽激素是以胞吐分泌的形式,被释放入细胞外的组织液中,经腺垂体内有孔型毛细血管吸收,进入血液循环发挥作用。近年来,李光容等应用透射电镜,观察了牛和大鼠腺垂体,在细胞间隙内,发现大小、形态及电子密度,与邻近腺垂体内分泌细胞内相似的颗粒。虞培玲和李肇特应用免疫胶体金标记法,用透射电镜观察到ACTH细胞的内分泌颗粒,在细胞膜下向细胞外突出,以及在细胞外观察到完整的免疫金标记分泌颗粒,推测ACTH细胞的分泌方式,除胞吐分泌外,可能还有类似于外分泌腺的顶浆分泌。王保芝等用电镜观察猴松果体、人胰岛组织和大鼠的神经垂体,均在细胞外血管周隙和组织间隙内,观察到完整的大型膜包分泌颗粒,认为松果体细胞、胰岛细胞和神经垂体分泌颗粒的外排形式,存在连同颗粒被膜的整体释放形式。以上种种迹象提示,腺垂体细胞的多肽激素分泌颗粒,也可能存在整体释放的分泌方式,并首先被转运到脑脊液中,但尚缺乏形态学方面的支持。第三,关于下丘脑与腺垂体之间的结构和功能联系,以及下丘脑释放的促垂体激素,是如何转运到腺垂体而发挥作用的。传统知识认为,下丘脑与腺垂体之间,没有直接的神经联系,它们之间借助垂体门脉系统,实现功能上的紧密联系。下丘脑促垂体区内的神经内分泌细胞,主要位于下丘脑的内侧基底部,其轴突投射到正中隆起,轴突末梢与垂体门脉的初级毛细血管丛接触,首先将下丘脑产生的调节肽,释放入垂体门脉,经垂体门脉血管运输至腺垂体,再从腺垂体内次级毛细血管丛(血窦)扩散出来,调节腺垂体细胞的分泌活动。但也有学者认为,下丘脑的调节肽,可以经过垂体门脉血管周围的组织间隙,直接输送到腺垂体而发挥作用。因此,本实验观察SD大鼠腺垂体的表面特征,内部的细微和超微结构特点;观察垂体周围是否存在软脑膜和蛛网膜;为腺垂体多肽激素直接释放入脑脊液的可能途径,下丘脑与腺垂体之间的结构和功能联系,提供形态学依据。一、腺垂体表面结构特点的形态学观察目的:探讨腺垂体周围是否存在脑组织周围的三层被膜。方法:通过组织切片的HE染色光镜观察,应用透射和扫描电镜,观察SD大鼠腺垂体表面的结构特点。结果:HE染色切片观察显示,在大鼠腺垂体表面,存在一层由单层上皮细胞构成的被膜,被膜下还有一薄层疏松结缔组织。扫描电镜观察显示,腺垂体表面是由单层扁平上皮构成的垂体囊,上皮细胞伸出许多指状突起,形成表面的微绒毛;相邻的上皮细胞之间,存在2-5μm的囊上皮孔。透射电镜观察显示,腺垂体包被有由单层扁平上皮和上皮下结缔组织构成的垂体囊。结论:在大鼠腺垂体周围,存在与脑组织表面延续的三层被膜。软膜性垂体囊表面,存在上皮孔、分泌颗粒及巨噬细胞等结构成分。二、腺垂体多肽激素释放入脑脊液途径的观察目的:探讨腺垂体肽类激素直接释放入脑脊液途径的结构基础。方法:对SD大鼠腺垂体的常规和DMSO冷冻割断电镜样品,进行了扫描和透射电镜观察。结果:扫描电镜观察显示,大鼠腺垂体表面的上皮细胞之间,存在2~5μm的囊上皮孔,上皮孔附近可见球形分泌颗粒,还观察到圆形和多突形巨噬细胞。透射电镜和DMSO冷冻割断样品的扫描电镜观察显示,腺垂体主要由各类腺细胞所组成,腺细胞之间存在大量大小不等的细胞间池;腺垂体内的毛细血管为窗孔(50nm)型,内皮外尚有基膜与血管周围结缔组织分隔,在细胞间池和血管周隙内,可见大量完整的膜包分泌颗粒(100~300nm)。结论:腺垂体多肽激素分泌颗粒的释放形式,存在连同颗粒被膜的整体释放;释放入腺垂体组织液中的多肽激素或分泌颗粒,更易通过细胞间池-血管周隙-囊上皮孔,直接进入蛛网膜下隙的脑脊液中。三、下丘脑与垂体之间的结构和功能联系目的:探讨下丘脑与垂体之间的结构和功能联系,以及下丘脑多肽激素是如何被转运到腺垂体发挥作用的。方法:对SD大鼠垂体柄进行了HE染色切片的光镜观察和超薄切片透射电镜观察。结果:光镜和电镜观察显示,垂体柄由被膜包裹,内含两类主要结构。一类是下丘脑至神经垂体的纵行纤维束,由粗细不等的无髓神经纤维组成,即视上—室旁垂体束;另一类是连接正中隆起和腺垂体毛细血管丛之间的数条垂体门脉。垂体门脉的血管,只由一层有孔内皮细胞构成,管径粗大,含有大量的血细胞,属于毛细血管性质;垂体门脉的血管之间,以及垂体纤维束周围,存在宽阔的疏松结缔组织,可见成纤维细胞和巨噬细胞。结论:下丘脑多肽激素经视上—室旁垂体束,运送到神经垂体释放;可通过垂体门脉系统输送到腺垂体,也可经垂体柄内组织间隙,直接输送到腺垂体而发挥作用。
[Abstract]:The pituitary gland is an important endocrine organ of the body. From embryology and histology, it can be divided into two parts of the adenohypophysis and the neurohypophysis, producing a variety of peptide hormones. In recent years, there are still some controversial problems in the study of the pituitary.
First, there are still different statements about whether there are three layers of membrane on the surface of the brain tissue around the pituitary. Some scholars believe that the pituitary bread is a capsule composed of the dura. Below the sellar septum, there is no arachnoid and pia around the pituitary, and the dura is closely attached to the pituitary. Far, the arachnoid omentum above the sellar septum is reflexed at the pituitary stalk, about 8%~56% of the individual, the arachnoid penetration into the hole, the depth of more 2mm., and it is believed that the arachnoid membrane can penetrate the saddle through the saddle diaphragm and form the subarachnoid space around the pituitary gland, which is recognized according to the sella sella image, and the arachnoid capsule around the hypophysis.
Second, on the release form and transport pathway of adenohypophysis polypeptide hormone, most scholars believe that adenohypophysis polypeptide hormone is released in the form of exocytosis, and is released into the tissue fluid outside the cell. It is absorbed through the pore capillary in the pituitary gland and enters the blood circulation. In recent years, Li Guangrong and other used transmission electron microscopy to observe the cattle. The size, morphology and electron density of the rat's pituitary gland were found in the space of the cell. The particles similar to that in the adjacent pituitary endocrine cells were found. Yu Peiling and Li Zhaote used the immunogold gold labeling method to observe the endocrine particles in ACTH cells by transmission electron microscope, protruding out of the cell under the cell membrane, and observing the integrity of the cells outside the cell. In addition to the secretion of ACTH cells, the secretion of the secretory granules of the ACTH cells may be similar to that of the exocrine gland. The monkey pineal body, the human islet tissue and the neurohypophysis of the rat are observed by electron microscopy. All the large membrane secretory granules are observed in the peripheral blood vessels and in the interwoven gap. It is considered that the pineal cells, islet cells and the neurohypophysis secrete the outer platoon form, and there is a whole release form together with the granular membrane. All the above indications suggest that the polypeptide hormone secreting particles in the adenohypophysis cells may also exist as a whole release form, and are first transported to the cerebrospinal fluid, but lack of morphological aspects. Support.
Third, the structure and function connection between the hypothalamus and the adenohypophysis, and the pituitary hormone released by the hypothalamus, how the pituitary hormones are transported to the adenohypophysis. Traditional knowledge holds that there is no direct neural connection between the hypothalamus and the adenohypophysis, which helps the hypophysis portal system to achieve functional close connections. The neuroendocrine cells in the hypothalamus, mainly located in the medial basal part of the hypothalamus, whose axons projecting to the median eminence. The axon ends in contact with the primary capillary plexus of the pituitary portal. First, the regulation peptide produced in the hypothalamus is released into the pituitary portal vein, transported to the pituitary by the pituitary portal vein, and then from the hypophysis. The capillary plexus (blood sinus) diffuses to regulate the secretory activity of the adenhypophysis cells. However, some scholars believe that the regulating peptide in the hypothalamus can be transported directly to the pituitary through the interstitial space around the blood vessels of the hypophyseal portal vein.
Therefore, we observed the surface features of the adenohypophysis of SD rats and the microscopic and ultrastructural features of the internal hypophysis, observed the presence of the pia meninges and arachnoid omentum around the pituitary gland, the possible pathway for the direct release of the pituitary polypeptide hormone into the cerebrospinal fluid, the structural and functional relation between the hypothalamus and the pituitary gland, and provided a morphological basis.
The morphological observation of the surface structure of the adenhypophysis
Objective: To investigate whether there are three layers of membranes around the pituitary gland.
Methods: HE staining of histological sections was used to observe the structural features of the hypophysis of SD rats by transmission and scanning electron microscopy.
Results: HE staining showed that there was a layer of membrane composed of monolayer epithelial cells on the surface of the rat adenhypophysis, and a thin layer of loose connective tissue under the membrane. The scanning electron microscope showed that the surface of the pituitary gland was a pituitary capsule consisting of a single layer of flat epithelium, and the epithelial cells extended a number of finger shaped protuberances and formed microvilli on the surface. Between the epithelial cells of the adjacent epithelium, there is a 2-5 m pouch on the surface of the capsule. The transmission electron microscope shows that the pituitary gland is a pituitary capsule consisting of a single layer of flat epithelium and an inferior connective tissue.
Conclusion: there are three layers of membrane that continue with the surface of the brain tissue around the pituitary gland of the rat. The surface of the soft membrane of the pituitary gland has the structural components such as the upper hole, the secretory granules and the macrophage.
Two, the release of polypeptide hormones from the adenohypophysis into cerebrospinal fluid.
Objective: To explore the structural basis of direct release of peptide hormones from the adenosine pituitary into cerebrospinal fluid.
Methods: the adenosine hypophysis of SD rats was examined by scanning electron microscope and transmission electron microscope (SEM) under conventional and DMSO freeze cutting electron microscope samples.
Results: the scanning electron microscope showed that the epithelial cells on the surface of the pituitary gland existed between the rat's adeno hypophysis, and there was a 2~5 mu m on the surface of the capsule. Spherical secretory granules were visible near the epithelial hole. The circular and multi process macrophages were observed. The scanning electron microscopy of transmission electron microscopy and DMSO frozen cut samples showed that the adeno was mainly composed of all kinds of gland cells. There are a large number of intercellular pools between different sizes; the capillaries in the pituitary gland are the 50nm type, and the outer membrane is still separated by the connective tissue around the vessels. In the intercellular pool and the perivascular space, a large number of intact membrane secretory granules (100~300nm) are visible.
Conclusion: the release form of the adenohypophysis polypeptide hormone secreting particles exists together with the whole release of the granular membrane, and the polypeptide hormones or secretory particles released into the tissue fluid of the adenohypophysis are more easily entered into the subarachnoid slots through the intercellular pool - the perivascular gap - the pouch on the subarachnoid space.
Three, the structural and functional connections between the hypothalamus and pituitary gland.
Objective: To investigate the relationship between the structure and function of hypothalamus and pituitary, and how the hypothalamus is transported to the adenohypophysis. Methods: the light microscopy and ultrathin section of the pituitary stalk of SD rats were observed by light microscopy and ultrathin section transmission electron microscopy.
Results: the optical and electron microscopic observations showed that the pituitary stalk was wrapped by the membrane and contained two main types of structures. One was the longitudinal fiber bundle of the hypothalamus to the neurohypophysis, composed of unamedullary nerve fibers with different thickness, that is, the paraventricular paramicular hypophysis bundles, and the other a few pituitary portal veins connecting the median eminence and the adenhypophysis capillaries. The blood vessels of the portal vein are composed of only one layer of porous endothelial cells. The diameter of the tube is large and contains a large number of blood cells. It belongs to the nature of the capillary; it is between the vessels of the pituitary portal vein and the hypophyseal fiber bundle. There are broad loose connective tissue, fibroblasts and giant macrophages.
Conclusion: the paraventricular paramparo pituitary bundle of hypothalamus is transported to the neurohypophysis and can be transported to the pituitary through the pituitary portal system, and can be transported directly to the pituitary by the interstitial space of the pituitary stalk.

【学位授予单位】：河北医科大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R322

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