中华绒螯蟹窦腺的显微和超微结构

借助光学和电子显微镜观察了养殖河蟹 1龄蟹种、早熟蟹种和 2龄成蟹窦腺的形态结构和神经分泌物质释放方式。河蟹窦腺位于眼柄视神经节内髓与终髓交界处背侧 ,活体为乳白色 ,扁球状 ,大小约为 0 5 5mm×0 45mm× 0 2 3mm。窦腺呈囊状 ,腺体壁由膨大的神经分泌细胞末梢和胶质细胞组成 ,神经末梢内充满电子致密的分泌颗粒。根据颗粒的大小、形态和电子致密度等特征 ,区分出 6种不同类型的神经分泌末梢。河蟹窦腺中的神经分泌物质以胞吐作用方式释放 ,一些现象表明 ,神经胶质细胞参与神经分泌颗粒的释放。 1龄蟹种、早熟蟹种和 2龄成蟹窦腺的形态、结构无明显差异 ,但神经激素颗粒释放情况明显不同 ,从形态结构上证实了窦腺对养殖河蟹性腺发育的调控作用。     

中华绒螯蟹窦腺神经末梢及X-器官神经分泌细胞的类型

在电子显微镜下观察了性未成熟的中华绒螯蟹黄蟹的窦腺及X－器官的超微结构。X－器官位于眼柄神经节终髓的腹外侧,与窦腺位置斜相对,窦腺主要由神经分泌细胞的末梢和胶质细胞组成。神经末梢含有大量的膜结构包围的颗粒、线粒体、粗面内质网和许多电子透明的小泡,末梢外周有时可见指状突起。依据颗粒的大小、形状、电子致密度以及胞质特征,可区分出6种类型的窦腺神经末梢及7种X－器官神经分泌细胞。观察了末梢中神经分泌颗粒的胞吐作用方式的释放过程,并且尝试对窦腺不同末梢中的颗粒及X－器官神经分泌细胞中的颗粒作了比较,发现二者之间具有较好的对应性,即电子致密度无大的变化,形态特征相似,只是大小稍有增加。     

北京鸭产卵期输卵管管状腺细胞超微结构研究

用电子显徽镜对北京鸭输卵管管状腺细胞进行观察。鸭输卵管由五部分组成:漏斗、蛋白分泌部、峡部、壳腺和阴道。蛋白分泌部的管状腺细胞有四种类型。A型细胞有电子密度深色颗粒;B型细胞充满了无定型低电子密度物质;C型细胞具有非常明显的粗面内质网和高尔基复合体;D型细胞是由致密的颗粒和低电子密度的颗粒所组成,腔内充满分泌颗粒。我们在这篇文章中分析了蛋白分泌周期的四个不同阶段。     

麝鼠泌香期香囊腺形态及组织结构的研究

麝鼠香囊腺由腺细胞、支持细胞和排香管组成。其分泌腺属复管泡状腺。发育初期的腺泡胞质内含有大量的粗面内质同、光滑内质网、高尔基复合体、中心粒和线粒体、香腺细胞间连接发达,桥粒、半桥粒广为分布。胞质内含有电子致密度高和电子致密度低的两种分泌颗粒。其分泌方式为顶浆分泌。     

优雅蝈螽雄性附腺的超微结构及其腺管提取物对精子束的作用

为阐明优雅蝈螽Gampsocleis gratiosa Brunner von Wattenwyl雄性附腺的结构与功能的关系, 本文利用透射电镜(transmission electron microscope, TEM)技术研究了优雅蝈螽雄性附腺的超微结构, 利用微分干涉相差显微镜(differential interference contrast microscope, DIC)技术并结合雄性附腺匀浆提取物与精子束在体外的短暂培养, 研究了优雅蝈螽雄性附腺对精子束的作用。结果表明： 优雅蝈螽雄性附腺3类腺管组织结构相似, 腺管管壁为单层上皮细胞, 缺少内表皮, 说明其来源于中胚层。上皮细胞富含粗面内质网、 线粒体、 高尔基体, 具有分泌细胞的特点。腺管管腔中分泌物有4种形态, 即电子透明的物质、 电子致密的颗粒物质、 细纤维状物质以及绒球状物质。上皮细胞的分泌方式主要有2种, 即顶质分泌和局部分泌。乳白短腺管的匀浆提取物参与了帽状精子束解聚的过程, 乳白长腺管和透明腺管的匀浆提取物有维持精子束活性的作用。本研究结果为进一步阐明螽斯雄性附腺的生理功能奠定了基础。     

麝鼠香腺发育及腺细胞培养分离的初步研究

目前麝鼠香是麝香最好的天然替代物,麝鼠香来源于麝鼠生殖系统中的香腺,已发现其香腺中分泌细胞和支持细胞是麝鼠泌香的关键。本研究通过组织形态、HE染色、免疫组织化学染色及免疫荧光鉴定方法,初步描述了麝鼠香腺的发育过程。麝鼠香腺的形态结构显示其由小到大再至非泌香期萎缩;HE染色及组化结果显示,香腺在发育初期富含颗粒饱满的腺泡,雄激素分泌处于较低水平,分泌细胞数量较少,随着进一步发育,雄激素水平及分泌细胞数量逐渐升高,在两个月时达到最高,腺泡逐渐变大成熟并开始释放麝鼠香等分泌物;在泌香末期,腺泡逐渐被结缔组织取代。以上结果将有助于麝鼠香腺发育及分泌机制的研究,为提高麝香产量及实现体外泌香建立基础。另外,我们成功分离并鉴定了分泌细胞和支持细胞,以期为后续建立体外泌香体系奠定基础。     

中华绒螯蟹胸神经团神经分泌细胞的显微和超显微结构观察

应用光学显微镜和电子显微镜技术,研究了中华绒螯蟹(Eriocheir sinensis)胸神经团的神经分泌细胞,描述了其显微和超显微结构。依据细胞形态、细胞核、内分泌颗粒和细胞质的特征将胸神经团神经分泌细胞分为3种类型:Ⅰ型细胞最大,胞质中存在许多大小不同的空泡,分泌颗粒数量很少;Ⅱ型细胞中等大小,细胞器发达,分泌颗粒数量较多,形态多样;Ⅲ型细胞最小,分泌颗粒数量最多,细胞器很少。     

正中隆起中的加压素有两个来源

在下丘脑室旁核的小细胞性神经元末梢有加压素(VP),这些神经元又可合成促肾上腺皮质激素释放因子(CRF)。已发现,VP和CRF存在于同一正中隆起外区纤维的神经分泌细胞颗粒中。但是,平行测定垂体门脉中的 VP 和 CRF 显示,VP 的浓度变化与 CRF 的浓度变化不相关,说明它们可能来源于不同部位。Holmes 等最近提出,VP 可能来源于正中隆起的两个区,其中一个区是正中隆起的外区,它可同时释     

问题解答

问神经激素与神经递质有什么不同? 答神经激素和神经递质都是细胞之间的化学信息分子。神经激素是神经分泌细胞的核周体产生的活性物质,沿着轴突输送至球状末梢,然后释放到血液中再作用于其靶细胞。神经递质是由神经细胞轴突末梢释放的化学物质,在二个神经元隔开的小间隙(突触)中扩散,或在神经元与效应器细胞间扩散。二者比较如下。     

神经肽Y免疫反应神经和细胞在大鼠颌下腺的分布

本研究应用免疫组织化学ＡＢＣ技术,观察了含神经肽Ｙ神经和细胞在大鼠颌下腺内的分布特点。结果显示：含神经肽Ｙ神经纤维主要走行于腺泡、导管及血管周围。颌下腺内神经节细胞和颗粒曲管细胞亦呈神经肽Ｙ免疫反应阳性。提示：大鼠颌下腺的腺体分泌和血液供应可能受神经肽Ｙ能神经调控。     

The ultrastructure of the sinus gland of the crayfish Astacus leptodactylus (Nordmann)

Summary An ultrastructural study of the sinus gland of the crayfish Astacus leptodactylus demonstrates that this gland is mainly composed of glial cells, axons and axon terminals. On the basis of the size, shape and electron density of the neurosecretory granules, we could distinguish five different types of axon terminals.     

Relationship between Rous sarcoma virus production in golden hamster cells and the cell cycle]

The axon terminals of neurosecretory cells, containing elementary granules of neurosecretory materials, have been described on the basis of light and electron microscopy. No allochthonous neurosecretory elements were found in the sinus gland. The discharge of the granules from some terminals of the sinus gland occur with the changed salinity of the environment. There is a great difference in the structure of the sinus gland when salinity is changed. The structure of the sinus gland and its modification under experimental conditions indicate a possibility of neurohormonal regulation of the hydromineral balance.     

Neurosecretion in the sinus gland of the fiddler crab,Uca pugnax

The ultrastructure of the sinus gland of the fiddler crab, Uca pugnax, was investigated and found to be similar to that in other crustaceans. Five types of neurosecretory axon terminals were tentatively identified on the basis of the size, shape, and electron density of granules within the axons. Release of neuro-secretory material appears to be by exocytosis.     

Fine structure of the neurohemal sinus gland of the shore crab,Carcinus maenas,and immuno-electron-microscopic identification of neurosecretory endings according to their neuropeptide contents

Summary The sinus gland of the shore crab, Carcinus maenas, is a compact assembly of interdigitating neurosecretory axon endings abutting upon the thin basal lamina of a central hemolymph lacuna. Four types of axon endings are distinguishable by the size distribution, shape, electron density and core structure of their neurosecretory granules. One additional type of axon ending is characterized by electron-lucent vacuoles and vesicles. The axon profiles are surrounded by astrocyte-like glial cells. Various fixations followed by epoxy- or Lowicrylembedding were compared in order to optimize the preservation of the fine structure of the granule types and the antigenicity of their peptide hormone contents. By use of specific rabbit antisera, the crustacean hyperglycemic, molt-inhibiting, pigment-dispersing, and red-pigment-concentrating hormones were assigned to the four distinct granule types which showed no overlap of immunostaining. Epi-polarization microscopy and ultrathin section analysis of immunogold-stained Lowicrylembedded specimens revealed that immunoreactivity to Leu-enkephalin and proctolin is co-localized with moltinhibiting hormone immunoreactivity in the same type of granule. The size and core structure of the immunocytochemically identified granule types vary little with the different pretreatments but, in some cases, to a statistically significant extent. The present results are compared with those from earlier studies of sinus glands in different crustaceans. The methods of granule identification used in this study supplement the classical approach in granule typing; they are easier to perform and more reliable for the analysis of release phenomena in identified secretory neurons supplying the neurohemal sinus gland.     

The ultrastructure of the sinus gland of Gammarus oceanicus (Crustacea: Amphipoda)

Summary The sinus gland of Gammarus oceanicus, like that of other crustaceans, is composed of three elements: neurosecretory axons, glial cells and stromal sheath. Five neurosecretory axon types are identified on the basis of granule diameter, shape, and electron density, and axon matrix density. Exocytosis appears to be the major release mechanism of neurosecretory material. The preterminal regions of neurosecretory axons contain axoplasmic reticulum and neurotubules. Their arrangement in the axon and relationship with one another suggest a transport function. Multilamellar bodies are found in the terminal regions of neurosecretory axons. They arise from mitochondria and may be involved in granulolysis.The technical assistance of G.A. Bance, statistical assistance of D. MacCharles and D.W. Hagen, and financial support provided by the University of New Brunswick Research Fund to K.H. are gratefully acknowledged     

The Cerebral Neurosecretory System,Secretory End-Foot System and Infracerebral Gland—a Probable Neuroendocrine Complex in Nephtys (Annelida; Polychaeta)

Abstract The brain of Nephtys contains four neurosecretory cell types with distinctive cytoplasmic inclusions, a cells are located uniquely in a single pair of ganglionic nuclei and b cells are represented by a single pair of cells, whereas c cells and d cells have a scattered distribution. Their axons form two types of secretory release structure. First, possible axon collaterals synapse upon slender “dentritic twigs” in the core of the brain. Secondly, two tracts descend to the brain floor to form a “neurosecretory neuropile” (or storage and release complex) in contact with the inner surface of the brain capsule. Other neurosecretory fibres penetrate through the capsule, branch extensively, and terminate in contact with its ventral surface in close association with the “infracerebral gland”. The gland is derived from the pericapsular epithelium and exhibits signs of specialization for glandular function. In contrast to certain other polychaetes, it does not contain secretory neuron perikarya. The secretory end-foot system is poorly developed. Its terminals are located adjacent to the neurosecretory neuropile, which they encircle. The cell bodies are probably represented by four e cells which, like the terminals, contain many mitochondria.     

Localization of crustacean hyperglycemic hormone (CHH) in the X-Organ sinus gland complex in the eyestalk of the crayfish,Astacus leptodactylus (Nordmann, 1842)

The eyestalk of Astacus leptodactylus is investigated immunocytochemically by light, fluorescence, and electron microscopy, using an antiserum raised against purified crustacean hyperglycemic hormone (CHH). CHH can be visualized in a group of neurosecretory perikarya on the medualla terminalis (medulla terminalis ganglionic X-organ: MTGX), in fibers forming part of the MTGX-sinus gland tractus, and in a considerable part of the axon terminals composing the sinus gland. Immunocytochemical combined with ultrastructural investigations led to the identification of the CHH-producing cells and the CHH-containing neurosecretory granule type.     

Ultrastructural study of the neurosecretory granules in the sinus gland of the blue crab,Callinectes sapidus

Summary Seven morphologically different types of neurosecretory granules have been found in the axon terminals of the sinus gland of the blue crab, Callinectes sapidus. They differ from each other in size, shape, staining characteristics, solubility characteristics, core matrix characteristics, axon terminal matrix characteristics, presence or absence of space between the granule membrane and granule core matrix, and frequency of occurrence. Five of the types are segregated in different axon terminals and are believed to represent different hormone-protein complexes. Two of the types, which have lost part or all of their granular contents, are thought to be variants of the other five types. The differences in granular morphology are better revealed by some fixation procedures than others. Palade's acetate-veronal buffered osmium tetroxide, in particular, reveals striking differences. The following observations suggest that different hormone-protein complexes are segregated in different axon terminals and that these complexes may be morphologically distinguished at the level of the electron microscope.Supported by USPHS-NIH Training Grant GM-00669 and Grant GB-7595X from the National Science Foundation.