大鼠下丘脑室旁核神经元的超微结构特征

在透射电镜下,我们观察到PVN大细胞具有四种不同的形态,认为属于同一类细胞分泌活性的不同时相:(1)合成相,粗面内质网非常丰富,(2)加工相:Golgi复合体发达,周围分布着一些神经分泌颗粒;(3)储存相:神经分泌颗粒明显增多:(4)转运相:细胞质内神经分泌颗粒很少,而在细胞周围可见一些充满神经分泌颗粒的突起。免疫电镜的结果也证实了VP阳性神经细胞具有类似的四种不同形态,其中在合成相,粗面内质网囊膜呈免疫阳性反应,还有一些PAP免疫复合物沉积在细胞质中。而在加工,储存和转运相,神经分泌颗粒呈免疫阳性反应。同样,小细胞亦具有三种不同形态特证,可能代表着不同的功能状态。     

胰组织结构提示多肽胰岛素的正常转运经淋巴而非门脉途径

目的　探讨胰岛多肽激素释放形式和细胞外正常转运途径的结构基础。方法　对大鼠和人胰尾部组织进行了光镜 (LM )和透射电镜 (TEM)观察。结果　胰组织主要由腺泡构成的腺小叶和分隔腺小叶的结缔组织所组成。胰腺的导管、血管和淋巴管 ,有髓和无髓神经纤维 ,均穿行于胰结缔组织内。在胰岛周围的结缔组织间隙内也可见到完整的膜包分泌颗粒 (2 0 0～ 5 0 0nm)。胰腺的毛细血管为窗孔 (5 0nm)型。结论　胰组织结构特点提示 :胰岛多肽激素的释放形式 ,可能是连同颗粒膜的整体释放而非传统认为的胞吐分泌 ;释放入胰组织液中的多态胰岛素或分泌颗粒 ,更易进入淋巴而非门脉血液     

大鼠下颌下腺卵泡刺激素、黄体生成素的分布及与促性腺激素释放激素受体的共定位研究

目的研究卵泡刺激素(FSH)和黄体生成素(LH)在大鼠下颌下腺中的定位、分布及与促性腺激素释放激素受体(GnRHR)共定位的关系。方法采用邻片免疫组织化学共定位方法。结果大鼠颌下腺浆液性腺泡上皮细胞、分泌管、排泄管及颗粒曲管上皮细胞均呈FSH和LH免疫反应阳性，阳性颗粒分布在细胞质内，细胞核阴性。邻片共定位结果显示颌下腺GnRHR免疫反应阳性细胞同样呈FSH免疫反应阳性，大部分的GnRHR免疫反应阳性细胞呈LH免疫反应阳性，小部分呈免疫反应阴性。两种免疫反应阳性物质均分布在细胞质内，细胞核阴性。结论大鼠下颌下腺浆液性腺泡上皮细胞、分泌管、排泄管和颗粒曲管上皮细胞可能以自分泌或旁分泌的GnRH调节自身合成与分泌FSH和LH。     

黄体生成素及其受体在大鼠胰腺的免疫荧光定位

目的观察黄体生成素(LH)及其受体(LHR)在SD大鼠胰腺的定位分布,以了解LH对胰腺的功能意义。方法选取SD大鼠12只,雌雄不拘,经腹腔注射戊巴比妥钠麻醉后,用4%多聚甲醛灌流固定2h,取出胰腺组织置于300g/L蔗糖液中,用于双标记免疫荧光定位研究,在激光共聚焦扫描显微镜下观察。结果胰腺部分外分泌腺细胞质、导管上皮细胞及部分胰岛细胞质LH反应阳性,小血管内皮细胞质呈LH弱阳性。部分胰岛细胞质呈LHR反应阳性,一些外分泌腺上皮细胞质呈LHR反应弱阳性,部分胰岛细胞及胰腺外分泌细胞质呈LH和LHR双阳性反应。结论LH可能通过旁分泌或自分泌的途径对胰腺的功能起调节作用。     

人表皮的冷冻复型电镜观察

本文应用冷冻复型法,对5例人小腿部脾经与胃经低电阻线下的表皮,进行了电镜观察。发现棘细胞具有粗大突起和微绒毛。颗粒细胞呈梭形,细胞表面呈波浪状;其胞膜的劈裂面上膜内微粒较棘细胞者少;但膜被颗粒的外排小孔则较之为多,其大小为50～75nm,平均数为47.5/μm~2;胞质内除个别线粒体外,主要为呈各种走向的张力细丝束;其间散布着膜被颗粒,接近角化细胞者多位于胞膜下方,直径为60～88nm。颗粒细胞核膜的膜内微粒及按孔均很稀少。角化细胞呈扁平状,胞膜明显增厚,其劈裂面上除桥粒区外,无膜内微粒和外排小孔;深层细胞的胞质可见大量细丝,而浅层者胞质呈均质状。桥粒在深层细胞多,至角化层渐减少,且呈退化状态。在颗粒层细胞间隙内,可见由膜被颗粒外排物质先附于细胞外表面,继而出现板层状膜及原纤维状结构,后者直径为70～100nm,具有间距为60～70nm的横纹。     

体外培养大鼠腺垂体细胞三氯化钐作用下的电镜观察

本实验应用细胞培养、扫描电镜、透射电镜及放射免疫等技术,以形态和功能相结合的方法,研究了三氯化钐(SmCl_3)对腺垂体细胞形态、超微结构及功能的影响.SmCl_3作用后,放免测定实验组细胞上清液中GH、LTH浓度较对照组明显增高,而TSH、FSH及LH浓度较对照组明显降低.电镜观察:实验组嗜酸性细胞质内的粗面内质网扩张、高尔基复合体发达,分泌颗粒增多且移向细胞的周边,细胞呈分泌及合成功能旺盛相;而实验组嗜碱性细胞数量减少,胞质中的分泌颗粒减少,细胞呈分泌及合成功能抑制状态,说明SmCl_3对腺垂体嗜酸性细胞的合成及分泌激素的功能有促进作用,对腺垂体嗜碱性细胞的合成及分泌激素的功能有抑制作用.     

神经垂体多肽激素分泌颗粒释放形式和转运途径的形态学研究

目的探讨神经垂体多肽激素分泌颗粒的释放形式和在细胞外正常转运途径的结构基础。方法对大鼠神经垂体进行光镜、透射电镜和扫描电镜观察。结果神经垂体主要由无髓神经纤维、垂体细胞及富含毛细血管的结缔组织组成。毛细血管内皮为有孔型(50nm)，外有基膜与血管周隙分隔。完整的大型膜包分泌颗粒(100～300nm)不仅大量存在于无髓神经纤维内，而且也见于血管周隙内。垂体囊由单层扁平上皮细胞和上皮下结缔组织构成，囊上皮细胞间存在许多不规则的囊上皮孔(2～5μm)，上皮孔附近经常可见分泌颗粒。结论这些结构特征提示，神经垂体多肽激素或分泌颗粒的释放形式，存在一种连同颗粒被膜的整体释放；释放入血管周隙内的多肽激素或分泌颗粒，更易经组织间隙、囊上皮孔进入脑脊液发挥旁分泌作用，而非直接通过毛细血管壁进入血液。     

大鼠、牛、猪和羊附睾上皮内富有PAS阳性颗粒细胞的组织学观察

本文对大鼠、牛、猪和羊的附睾组织,取其头、体和尾三段,用PAS等方法染色,作光镜观察。发现这些动物的附睾上皮中,夹有一种富有PAS阳性颗粒的细胞,颗粒内含中性多糖,其分泌方式为顶浆分泌。HE染色中的亮细胞,可能是分泌颗粒排出后的PAS阳性细胞。此外,在输精管起始段的上皮中,亦偶见有这种PAS阳性颗粒细胞。     

国人皮肤麦克尔细胞及其颗粒和亮小泡的超微结构观察

本文首次报道了国人皮肤麦克尔细胞(MC)及其颗粒和亮小泡的超微结构。MC多分布在触盘增厚的表皮基底层,与神经终末接触并形成突触样结构,与角质形成细胞以桥粒相联系。ME具有一分叶状核。丰富的线粒体和许多直径80—120nm的膜包致密核心颗粒和直径70～90nm的亮小泡。这些颗粒和小泡不仅靠近突触样结构膜,也靠近与角质形成细胞相邻的胞膜。本文还讨论了MC分泌功能的可能性。     

分泌颗粒素Ⅱ和促肾上腺皮质激素在脑损伤大鼠垂体腺细胞共存(英文)

采用荧光双标记技术研究了脑损伤时大鼠垂体前叶促肾上腺皮质激素和分泌颗粒素 的定位。垂体前叶细胞呈现分泌颗粒素 染色强阳性 ,阳性物质位于胞浆中。免疫荧光双标记技术用于鉴定分泌颗粒素 和促肾上腺皮质激素共存的细胞 ,共聚焦显微镜观察显示促肾上腺皮质激素和分泌颗粒素 共存于同一细胞。结果表明 :分泌颗粒素 可在大鼠垂体前叶促肾上腺皮质激素阳性细胞表达 ,其生理作用可能是调节分泌泡的 p H值以利于促肾上腺皮质激素从其前体裂解。     

Fine structural criteria for pituitary thyrotrophs in immature and mature rats

Fine structural criteria for identifying thyroid-stimulating hormone (TSH) cells in immature and mature rats have been studied by a modified superimposition technique. On days 10 and 20, some small oval immature TSH cells are scattered individually throughout the glandular tissue with a peripheral immunoreactive rim resulting from the sparse distribution of minute secretory granules less than 50 nm in diameter. The immunostained stellate TSH cells are clustered and have secretory granules 50–100 nm in diameter at the cell margins. On day 60, a few small immature TSH cells still remain. Although a few polygonal TSH cells that may not fully mature accumulate secretory granules 100–150 nm in diameter at the cell margins, the majority of TSH cells take the form of large stellate cells filled with secretory granules with the corresponding diameter, and surround an acidophil. These stellate TSH cells are characterized by dense arrangement of parallel arrays of rough endoplasmic reticulum (rER) or rER cisternae. The clustered or isolated elongate TSH cells are also observed to be vesiculated and to have numerous secretory granules 150–250 nm in diameter. In addition, large oval vesiculated TSH cells storing numerous secretory granules 150–250 nm in diameter appear sporadically in the gland, ultrastructurally resembling the gonadotrophs. It is concluded that the rat TSH cell is not a single type with a particular ultrastructure, but modifies its morphology according to its maturation or functional phase.     

On the fine structure of the Mehlis gland cells in the liver fluke,Fasciola hepatica L.

Summary The cells of Mehlis's gland in the liver fluke (Fasciola hepatica L.) have been studied with light and electron microscopy. The gland contained large cells in the periphery and small cells in the centre. The large cells presented morphological features characteristic of secretory cells, viz. large nucleoli, cytoplasmic basophilia, a well developed endoplasmic reticulum, abundant ribosomes, and secretory granules in different stages of development. The mitochondria were moderately frequent. Several small groups of vesicles and membraneous lamellae reminiscent of Golgi complexes occurred randomly in the cytoplasm. These structures were associated with mitochondria and secretory granules. Evidence of alterations and conversion into a cell débris was observed, and a process of holocrine secretion was suggested.The small cells were strongly basophilic, contained numerous ribosomes and mitochondria, and a few dense bodies. The internal membranes were few. The small cells had a primitive appearance and showed no secretory properties.With 7 Figures in the TextSupported by a grant from the Swedish Agricultural Research Council.     

Fine structure of canine Kupffer cells and their microtubule-containing cytosomes

The ultrastructure of Kupffer cells of canine liver has been studied and described. Kupffer cell nuclei were elongated and irregular in shape having a prominent double nuclear envelope containing scattered ribosomes on the outer membrane. Mitochondria were small, relatively scarce, and contained few mitochondrial granules. Elements of endoplasmic reticulum were scarce and highly irregular in form. In general, the cytoplasm was less dense than hepatocytes and contained fewer organelles which were less compactly arranged than in hepatocytes. Microbodies were not observed in any of the Kupffer cells studied. The cytoplasm contained various numbers of large phagosomes but consistently contained numerous dense cytosomes of various sizes. The most striking finding was that many cytosomes and phagosomes contained large numbers of short microtubules approximately 350 Å in diameter which were arranged in clusters and were associated with membanes.     

Structure of taste buds in foliate papillae of the rhesus monkey,Macaca mulatta

Taste buds in foliate papillae of the rhesus monkey were examined by electron microscopy. Three distinct cell types were identified. Type I cells were narrow elongated cells containing an oval nucleus, bundles of intermediate filaments, several Golgi bodies, and characteristic apical membrane-bounded dense granules. These cells exhibited morphological variations: some had a moderately dense cytoplasm, perinuclear free ribosomes, and flattened sacs of rough endoplasmic reticulum; others had a more lucent cytoplasm, dilated irregular rough endoplasmic reticulum, lysosome-like dense bodies, and lipid droplets. Type II cells typically contained a spherical, pale nucleus, a prominent nucleolus, supranuclear and infranuclear Golgi bodies, mitochondria with tubular cristae, and one or two centrioles. This cell type, too, showed some variation in the relative amounts of ribosomes and smooth endoplasmic reticulum, which varied inversely with each other. Type III cells were characterized by a clear apical cytoplasm essentially devoid of ribosomes and containing microtubules. In a few type III cells, the peri- and infranuclear regions contained many ribosomes and some rough endoplasmic reticulum. In most Type III cells, there were large numbers of dense and clear vesicles in the peri- and infranuclear regions; some of the vesicles were grouped in synapse-like arrangements with adjacent nerves. The morphological variations exhibited by all three cell types could be accounted for by age differences in each of the cells. This would be consistent with the notion that cell renewal occurs in each of the three cell populations.     

Immunohistochemical identification of mouse adenohypophysial gonadotropes

Mouse pituitary gonadotropes were identified using immunohistochemical techniques with OsO4 single fixation. Most gonadotropes are immunostained with both LH beta and FSH antisera (FSH/LH gonadotropes), whereas a few gonadotropes are positive only for LH beta (LH gonadotropes). The former gonadotropes are large rounded or oval cells and contain two types of secretory granules: electron-dense smaller ones (about 100-200 nm in diameter) and electron-transparent larger ones (maximum diameter, about 400 nm) enclosed by a halo. The endoplasmic reticulum appears as a series of dilated sacs, and the Golgi apparatus is distinct. The mitochondria are found to have an electron-dense matrix throughout the cytoplasm, but are often concentrated in and around the region of the Golgi apparatus. These fine structural features are somewhat similar to those of the classical Barnes "FSH cell" The LH gonadotropes are polygonal cells of medium size. Small granules, as described above, are seen, but large granules are not. The Golgi apparatus is distinct, but small. The LH gonadotropes resemble neither the Barnes "LH cell" nor the Kurosumi-Oota "LH cell".     

Immunoelectron microscopic studies of gonadotrophs in the male and female rat anterior pituitaries, with special reference to their changes with aging.

Gonadotrophs immunocytochemically identified with an antibody to LH beta were studied in both male and female rats of various ages, viz., 2, 14 and 23 months after birth. The rat gonadotrophs are classified into two cell types, i.e., Type I containing large (300-700 nm) and small (150-200 nm) secretory granules, and Type II containing only small (100-200 nm) secretory granules. In normal young adults, the male rat pituitary contains a large number of Type I cells (more than 90% of all gonadotrophs), whereas the female pituitary contains much more Type II cells (more than 70%) than Type I cells. With age, Type I gonadotrophs in the male rat pituitary decrease remarkably to less than 25%, while Type II cells constitute more than 70% at the age of 23 months; the ratio of Type I to Type II comes to be the same as in the female. The main cause of this change is the decrease in the number of large secretory granules as the animal ages. FSH and LH levels in both the pituitary and serum were determined by radioimmunoassay. Pituitary FSH content decreased gradually in the male with age, while that in the female showed no change. LH content in the male decreased slowly, but LH in the female increased with aging. The large secretory granules indicating the presence of FSH markedly decreased with aging. The Type II cells contain only small secretory granules which probably contain LH. Thus the results of morphological counting of each type of gonadotroph and those of radioimmunoassay of gonadotropins during aging were essentially parallel. Some signs of degeneration were observed in the gonadotrophs in the aged rat pituitaries.     

Ultrastructural evaluation of adenocarcinomas derived from apocrine glands of the anal sac associated with hypercalcemia in dogs.

Adenocarcinomas derived from apocrine glands of the anal sac and associated with persistent hypercalcemia in dogs were composed of tumor cells with numerous profiles of rough endoplasmic reticulum, clusters of free ribosomes, and a prominent Golgi apparatus. Neoplastic cells contained microtubules, microfilaments, tonofibrils, and had two types of electron-dense granules. Large lysosomelike dense bodies ranged from 0.6 to 2.2 microns in diameter and had a poorly delineated limiting membrane. Small granules (150-400 nm in diameter) had a sharply delineated limiting membrane with a narrow submembranous space and a homogeneous dense core. These smaller granules usually were located near the apexes of neoplastic cells, whereas the larger granules were situated near the base of cells. Apocrine cells in glands of the anal sac from control dogs that were in the secretory phase were columnar and had large dilated profiles of rough endoplasmic reticulum. Membranes of the endoplasmic reticulum fused with the plasmalemma and appeared to secrete their product directly into the lumens of acini, characteristic of merocrine secretion. Apical blebs of electron-lucent cytoplasm pinched off from nonneoplastic aprocine cells and were released into glandular lumens. Similar electron-lucent cytoplasmic blebs were present at the apexes of tumor cells. Myoepithelial cells were present between the epithelial cells and basement membrane in normal apocrine glands and were absent in neoplasms derived from these glands. Identification of the contents of the secretory-like granules in tumor cells and characterization of the hypercalcemic factor in the plasma or tumor tissue from dogs with this syndrome will help explain the pathogenesis of hypercalcemia associated with malignancy in animals and man.     

Parvalbumin in cortical epithelial cells of the pigeon thymus

We examined the distribution of parvalbumin in the pigeon thymus by light and electron microscopic immunohistochemistry. Tissues were also examined by conventional electron microscopy to determine the ultrastructure of immunoreactive cells. Parvalbumin immunoreaction was located in epithelial cells of the cortex, which formed dense mesh-like structures. Parvalbumin-positive epithelial cells were classified into 2 types. The first comprised elongated cells. In these, the nucleus was spindle-shaped, oval, or triangular, with a slightly irregular contour and contained rich heterochromatin peripherally. The cytoplasm was pale and processes extended laterally or ramified among the surrounding thymocytes. This type of cell formed the majority of immunoreactive cells. The other cell type consisted of polygonal epithelial cells. The nucleus was oval with deep indentations. Euchromatin occupied a large part of the nucleus. The cytoplasm contained numerous cell organelles compared with the elongated type, in particular, electron-dense vacuoles of various sizes and often bundles of tonofilaments. Both types of epithelial cell were interconnected by desmosomes. No secretory granules were found in the cytoplasm of elongated or polygonal cells. These results indicate the presence of heterogeneous group of parvalbumin-immunoreactive epithelial cells and suggest the likelihood of different functional roles for parvalbumin in the pigeon thymus.     

松果体的神经支配

电镜观察松果体实质,证明充满联合神经分支的薄层有神经纤维,这些纤维与明、暗细胞及神经胶质细胞的胞体和突起紧密相贴。接触点,胞膜增厚,髓鞘内主致密线消失,周期间线空隙加宽,出现施兰氏切迹样结构。无髓交感神经纤维终末膨大,含致密中心小泡,多分布于松果体细胞旁及血管周。本文阐明松果体系由联合神经及交感神经双重支配。     

Ultrastructure of the parotid gland in the little brown bat

The ultrastructure of the parotid gland was examined in the little brown bat. The seromucous acinar cells contained abundant granules of variable morphology. These granules were characterized by a submembranous dense layer consisting of fine parallel slats. In some bats, the matrix of the granules was structureless, whereas in others it consisted of closely packed but randomly arranged bundles of tubules. The intercalated ducts had a highly developed rough endoplasmic reticulum, often containing large numbers of intracisternal granules. In contrast, only a few secretory granules were present in the supranuclear cytoplasm. The striated ducts, which exhibited the characteristic basal striations consisting of vertically oriented mitochondria and highly folded plasmalemmas, contained numerous small dense granules in a subluminal band. These granules had a paracrystalline substructure with a periodicity of 8 nm. Excretory ducts strongly resembled striated ducts. They showed the same kind of basal striations and about half their constituent cells contained small paracrystalline granules.