首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 156 毫秒
1.
目的:阐明非酒精性脂肪肝病(NAFLD)的超微结构特点。方法:收集我校和其他单位送检的3例单纯性非酒精性脂肪肝,16例NASH患者和4例NAFLD肝硬化患者的肝穿刺组织。用2.5%戊二醛、1%锇酸双固定、Epon 812包埋,超薄切片70nm,醋酸铀和柠檬酸铅染色后,JEM-2000EX透射电镜观察。结果:单纯性脂肪肝患者主要表现为大小不等的脂滴沉积、以小脂滴为主,可互相融合。NASH患者的肝细胞都可出现大量脂滴积聚,为大小脂滴混合型、内容物主要为中等电子密度、比较均一的甘油三酯,部分脂滴周围可见磷脂成分,NASH患者肝细胞内脂滴也互相融合。肝细胞线粒体的超微结构改变包括多形性线粒体、基质颗粒增多、线粒体增大和嵴的丧失是主要的电镜异常发现,线粒体内还可见副晶格样包涵体。部分NASH患者肝细胞内可见Mallory小体。NASH患者肝细胞周围可见淋巴细胞浸润。肝血窦Kupffer细胞增生不明显,NAFLD肝硬化患者Disse间隙和肝细胞间可见胶原纤维增生。结论:NAFLD具有较为明确的超微结构改变,电镜检查有助于诊断。  相似文献   

2.
不同生殖期鳜肝脏超微结构变化的观察   总被引:16,自引:0,他引:16  
应用透射电镜对生殖季节与非生殖季节鳜肝脏超微结构的变化进行了观察。鳜肝细胞含有单个卵圆形的核,核仁清楚;细胞质内含有粗面内质网、线粒体、糖原颗粒和脂滴等细胞器和内含物。胆小管由相邻的数个肝细胞质膜凹陷围成,而肝血窦则由内皮细胞的胞质构成。还发现了贮脂细胞、枯否氏细胞和成纤维细胞。胆小管腔和窦周隙内浸润许多由肝细胞发出的微绒毛结构。鳜肝细胞的超微结构在产卵前后呈现明显变化:产卵前的肝细胞内富含线粒体、糖原颗粒和脂滴,粗面内质网发达;而产卵后的肝细胞内核仁发生迁移,部分细胞核囊泡化,糖原颗粒和脂滴排空,少数肝细胞具双核结构。非生殖期多数肝细胞核含有双核仁结构,胞质内溶酶体数量增多。  相似文献   

3.
氯化镨在小鼠肝脏细胞中形成含镨致密体   总被引:3,自引:0,他引:3  
本实验给小鼠4次注射氯化镨(总剂量为200mg/kg)后,光镜发现肝细胞呈嗜酸变性或空泡变性,肝细胞与枯否细胞中酸性磷性酶阳性的溶酶体增多。电镜观察到肝细胞出现程度不同的核变形、内质网扩张、糖原缺乏、溶酶体含较多高电子密度微粒。肝细胞与枯否细胞中均出现由高电子密度微粒聚集形成的致密体,应用X射线微区分析术可测到镨特征性能谱峰。  相似文献   

4.
巴西橡胶树乳管分化的超微结构研究   总被引:5,自引:0,他引:5  
用电子显微镜技术研究了巴西橡胶树(Hevea brasiliensis Mnll.Arg.)幼苗初生乳管分化的早期阶段,着重研究了乳管特有的结构成分的形成。最初可辨认的橡胶粒子出现在细胞质中,直径40—60nm,呈均匀的电子致密体;随着橡胶粒子的增大,粒子的中央区变为电子透明的,而周缘保持有电子致密物质,有时看到充满电子致密物的突起。观察到黄色体(本质为分散的溶酶体液泡)可由内质网膨大形成。在乳管发育过程中出现三种具有不同内含物的黄色体:最初的黄体含有染色很深的呈束状的微纤维,它们随后被含有浅色微纤维的黄色体所代替,成熟乳管的黄色体则含有杂乱的细纤维。在乳管分化初期,乳管细胞中不存在具有特殊结构的 F-w 复合体,只有许多与分生组织中的原质体相同的质体。观察到一些发育异常的乳管,它们似乎停留在发育的早期阶段,而不能继续发育成为典型的成熟乳管。  相似文献   

5.
河鲈锚首吸虫体壁的超微结构观察   总被引:1,自引:0,他引:1  
高谦  聂品 《水生生物学报》2003,27(3):221-226
寄生鳜鳃部的河鲈锚首吸虫的体壁由表皮合胞体、基板、环肌、纵肌和表皮细胞核周体所组成。合胞体顶部质膜起伏形成表皮的嵴纹,基部质膜折叠形成指状突起伸入到合胞体中。合胞体表面覆盖着一层糖萼。河鲈锚首吸虫的表皮中含有四类分泌体,即电子致密的分泌颗粒、中等电子致密的分泌颗粒、有膜包围的电子稀疏的分泌体和多囊体.可见分泌体和合胞体基质通过胞吐作用排到体外,未见吞饮小泡,推测表皮的主要功能在于分泌和渗透压调节而非营养吸收。在外侧头瓣的乳突状结构所在处,合胞层较薄,基板平滑,在实质组织中的一腔体样结构中可见囊状体、电子致密度各异的颗粒体、泡状体和电子致密的基质团,神经突起分布于腔体周围,这类乳突可能代表一类新的非纤毛感受器类型。  相似文献   

6.
目的 探讨中度海拔高度地区慢性低氧大鼠心肌、肝的组织学及超微结构变化。方法 本实验用Wistar大鼠20只,雌雄各半,六日内从海拔5米运至海拔3418米饲养,8周后断头处死大鼠,留取心肝组织作光电镜观察,同时高原暴露前后测定血RBC数及Hb含量。结果 心肝组织学改变主要为细胞水肿,即心肌颗粒变性,肝细胞疏松化,其次为心肌、肝细胞嗜酸性变。心肌组织有少量小灶状坏死,肝组织中未见坏死。超微结构主要有肌浆网扩张,线粒体肿胀,糖元颗粒减少,未见不可逆性损伤如线粒体出现杆状嵴、三膜嵴及核染色质边聚现象。毛细血管内皮细胞多有突起伸向管腔,胞质空泡变性,微饮泡较少。另外,高原暴露后RBC数及Hb含量明显升高。结论 该海拔地区慢性低氧大鼠心肌、肝组织及毛细血管的病变是可逆性的; 左右心室病变程度无显著性差异; 肝组织的病变程度明显轻于心肌组织。  相似文献   

7.
中国大鲵肝脏的超微结构   总被引:2,自引:1,他引:1  
方展强 《四川动物》2006,25(2):228-230
应用透射电镜对中国大鲵的肝脏进行了超微结构研究.观察表明,大鲵肝不具肝小叶,与其他脊椎动物有所不同.肝细胞含有单个卵圆形的核;细胞质内含有粗面内质网、高尔基囊泡、线粒体、糖原颗粒和脂滴等细胞器和内含物.胆小管由两个相邻肝细胞质膜凹陷围成,而肝血窦则由内皮细胞的胞质构成.胆小管腔和窦周隙内浸润许多由肝细胞发出的微绒毛结构.还发现了枯否氏细胞和贮脂细胞.还讨论了中国大鲵肝脏的一般形态结构特点.  相似文献   

8.
对湖北钉螺指名亚种(Oncomelania hupensis hupensis)肝脏的显微和超微结构作了较详细的研究。肝腺管壁由单层柱状上皮细胞构成。上皮细胞内,粗面内质网呈多层次板层状,主要分布于核周围,线粒体有椭圆、杆状两种形态,核上万有高尔基复合体并多有溶酶体出现。胞质中分泌颗粒分为四种,细胞基部的颗粒电子密度很高,中部有巨大颗粒,近细胞游离端的大、中、小分泌颗粒可连同胞质一起排放入管腔。在肝脏间质中的网状细胞多呈三角形状,有血细胞团和毛细血管腔构造。  相似文献   

9.
绒山蝠肝细胞电镜观察和乳酸脱氢酶同工酶的研究   总被引:1,自引:0,他引:1  
本文用光镜和电镜观察了绒山蝠肝细胞的超微结构,用聚内烯酰胺凝胶电泳,对肝组织LDH同工酶进行了研究。肝细胞有丰富的线粒体、内质网、核糖体,发达的高尔基体、溶酶体等。在线粒体的周围有一层粗面内质网包绕,二者的密切关系,不仅在绒山蝠其他组织中,且在大部分哺乳动物细胞中均未观察到。该种肝细胞的LDH同工酶以M亚基为主,主要催化丙酮酸还原成乳酸。  相似文献   

10.
研究了不同Zn^2+浓度对中华绒螯蟹(Eriocheir sinensis)Zhao状幼体肝胰细胞超微结构的影响。当Zn^2+浓度超过200μg/L时,与对照组相比,肝胰腺结构受到了显著的影响。成熟和正在形成的B细胞的空泡中有很多含有金属的电子致密颗粒(EDG,可能为金属蛋白复合本),随着B细胞的成熟和B细胞从肝胰腺管壁上脱落,这些DG也被释放到管腔中,因此肝胰腺的管腔中常有许多此类颗粒存在。B细  相似文献   

11.
ELECTRON MICROSCOPY OF LYSOSOME-RICH FRACTIONS FROM RAT LIVER   总被引:2,自引:0,他引:2       下载免费PDF全文
A preliminary electron microscope study has revealed the presence in lysosome-rich fractions, isolated from rat liver, of hitherto undescribed cytoplasmic particles, called "dense bodies." Approximately 0.37 µ in length, the dense bodies often possess an internal cavity and external membrane. They contain many electron-dense granules 55 to 77 A, or less, in diameter. Such dense bodies are also visible in electron micrographs of parenchymatous cells in liver sections. The correlations between dense bodies and lysosomes are listed, but until pure preparations are available it is not possible to assert that dense bodies and lysosomes are identical.  相似文献   

12.
Highly pure lysosomes were isolated from buffalo(Bubalus bubalis) kidney cortex by a procedure involving differential and isopycnic Percoll density gradient centrifugations. Arylsulphatase, N-acetyl-Β-glucosamindase and cathepsin D in the lysosomal preparation were 26–45-fold enriched over the homogenate. The purified lysosomes contained less than 0·06% of mitochondrial, microsomal and peroxisomal marker enzymes. In the electron micrographs the particles appeared as large dense granules of size 0·3-1·9 μm with no apparent structural features belonging to mitochondria or microsomes. The isolation procedure was also found to be suitable to obtain highly pure lysosome particles from renal cortex of other sources such as rat, lamb and beef. No ultracentrifugation steps were involved in the procedure  相似文献   

13.
本实验分别给小鼠腹腔与静脉隔日交替注射稀土元素化合物氯化铈、氯化铕、硝酸钆、葡萄糖酸铽,共五次,总剂量为300~630mg/kg。电镜观察显示,四种元素均于枯否细胞和肝细胞中形成凝集体,枯否细胞中尤多。应用X射线微区分析术于凝集体分别探测到四种稀土元素的特征性X射线能谱峰。两种细胞的溶酶体内含较多高电子密度微粒。于胆小管腔亦发现高电子密度微粒群,提示肝细胞中的稀土元素可随胆汁排出。本文描述了四种稀土元素引起的肝脏形态学变化。  相似文献   

14.
The intracellular distribution of iron and other elements was examined in various cell types in larvae and juveniles of the sea lamprey (Petromyzon marinus) using transmission electron microscopy and energy dispersive x-ray microanalysis. The objective was to establish whether there are cell-type specific relationships between iron and other elements in the iron-rich organs and tissues (adipose tissue, opisthonephric kidneys, dorsal integument, fat column, liver, and posterior intestine) of these two life cycle periods. Iron was localized within either dense bodies (presumptive lysosomes, siderosomes) or in the cytoplasmic matrix of many cell types where it was viewed as haemosiderin/ferritin and ferritin, respectively. Presumptive lysosomes of adipocytes of the nephric folds, dorsal integument, and fat column possessed iron and sulphur and this elemental association was also prevalent in the epithelia of the larval proximal tubules and in the posterior intestine and epidermis of both life periods. Macrophages of the larval haemopoietic tissue (posterior intestine) and of the juvenile opisthonephros, which were described as melanomacrophages because of their granules, possessed iron, sulphur, and calcium. This elemental association was also noted in the presumptive lysosomes of the iron-loaded hepatocytes of the juvenile liver while no elements could be detected in these cells in the larval organ. The variations and similarities in elemental associations between the cell types in each life period and at different life periods is discussed in the context of specific cell functions related to the prevention of iron toxicity. These functions are sequestration of iron and storage as the less toxic haemosiderin (larval adipocytes, macrophages, juvenile hepatocytes) or as part of a process of elimination of excesses of this metal (posterior intestine, dorsal epidermal cells). Due to its unique ability to deal with copious amounts of iron at all periods of the life cycle, the lamprey serves as an important model for studies of iron loading in vertebrates.  相似文献   

15.
Cathepsin D localization was studied in the liver of white rats by ultrastructural cytochemistry. It was shown that the product of reaction was present in lysosomes of hepatocytes, Kupffer's and endothelial cells and in fibroblasts from portal tracts am small granules or their conglomerate of different electron density. The lowest activity of cathepsin D was observed in hepatocytes, the most intensive reaction--in Kupffer cells. The extracellular activity of cathepsin D in vivo was revealed. It means that besides participation in intracellular degradation of different proteins, cathepsin D is secreted to extracellular space by liver cells (hepatocytes, Kupffer cells, fibroblasts) and it may participate in catabolism of intercellular matrix.  相似文献   

16.
Peroxisomes contain a system for beta-oxidation of fatty acids which differs from the mitochondrial system and is associated with hydrogen peroxide formation. We show that two enzymes: enoyl-CoA hydratase and 3-ketoacyl-CoA thiolase of the peroxisomal system are present in specific granules of rat eosinophils. Both enzyme proteins were purified from rat liver and monospecific antibodies were raised in rabbits. Eosinophils from peripheral blood and tissue eosinophils from the wall of intestine, fixed by glutaraldehyde and embedded in Epon were investigated. The postembedding immunocytochemical procedure with protein A-gold technique was used. The gold particles representing the antigenic sites for both enzymes were present only in specific granules of eosinophils with no immune deposits in mitochondria, nucleus and the cytoplasm. Although gold particles were found over the entire domain of the granule, the electron dense paracrystalline inclusions contained more gold than the granule matrix. Control preparations incubated with nonspecific IgG and protein A-gold complex alone were negative. These findings indicate that in specific granules of eosinophils both peroxisomal and lysosomal enzymes share the same intracellular compartment. The peroxisomal lipid beta-oxidation in eosinophils may be involved in generation of hydrogen peroxide, which has a crucial role in killing of metazoon parasites.  相似文献   

17.
The ultrastructure of the membranes of noradrenaline (NA) and adrenaline (A) granules of the bovine adrenal medulla (Terland, O., T. Flatmark, and H. Kryvi, Biochim, Biophys. Acta 553, 460--468 (1979)) was analyzed by transmission, negative staining and freeze-etch electron microscopy. The two types of storage granules can be distinguished mainly by two morphological criteria: (a) The NA-granules have a more electron dense matrix core than the A-granules, (b) the NA-granules revealed less asymmetry in the distribution of intramembrane particles (nPF:nEF = 4,5:1) than the A-granules (nPF:nEF = 9:1). Thus, the trilaminar structure, negative staining pattern and size distribution of the intramembrane particles of the two fracture faces on freeze-etch electron microscopy were very similar for the two types of granules. Freeze-etching revealed a wide range of the particle size distribution for both fracture faces in both types of granules, with an average diameter of 12.6 +/- 2.7 nm (A-granules) and 10.2 +/- 2.8 nm (NA-granules) for the E-fracture faces and 11.4 +/- 2.7 nm (A-granules) and 9.8 +/- 2.4 nm (NA-granules) for the P-fracture faces. Some of the particles on the P-fracture face (outer surface of the membrane) revealed a subunit structure, most clearly seen in the specimens of NA-granules. Morhpometric analyses of sectioned bovine adrenal medulla revealed that the chromaffin granules on an average account for approx. 13.5% of the cytoplasmic volume in the total population of chromaffin cells.  相似文献   

18.
Cardiac conducting fibers were selected from two dogs defined as A and B. The specimens differed in the reaction of their electron dense granules, commonly referred to as glycogen, to the treatment en bloc with uranyl acetate. Material was fixed in glutaraldehyde and OsO4. Blocks were processed either conventionally or immersed in uranyl acetate before dehydration. Sections were examined unsatined, stained with U and/or Pb or with a histochemical technique (PA-TSC-SP) specific for glycogen. Electron dense granules have affinity to Os, U and Pb which suggests ionic reactions specific for protein but improbable for glycogen. Large granules in A turned into pale ghosts and small granules in B disappeared after treatment en bloc with uranyl acetate. PA-TSC-SP in conventional samples showed glycogen particles arranged into aggregates corresponding in size to the electron dense granules. Treatment en bloc slightly affected glycogen aggregates in A and resulted in a formation of large clumps of glycogen particles in B. It was concluded that the electron dense granules represented protein bound to glycogen in the organelles called glycosomes. Acidic action of uranyl acetate removed protein from glycosomes. The degree of this removal depended on the amount of protein present in glycosomes in the moment of fixation.  相似文献   

19.
Small pieces of liver from rats subjected to different dietary regimes were fixed by freeze-drying, and postfixed by in vacuo heating and denaturation with alcohol. Specimens were digested with ribo- or deoxyribonuclease, and stained with gallocyanin-chromalum, azure II, the Feulgen procedure or alcoholic platinic tetrabromide. Some specimens were reserved as controls of the effects of enzyme treatment. Stained and unstained specimens were embedded in methacrylate and examined by light and electron microscopy. Basophilic and Feulgen-positive substances, after contact with watery reagents, were found by electron microscopy to exist as small dense granules embedded in a less dense homogeneous matrix, forming the walls of submicroscopic vacuoles. These granules were absent after digestion with nucleodepolymerases. In specimens (unstained, or stained with platinic tetrabromide) which had not passed through water, the dense (basophile) substances in nuclei and cytoplasm were found to exist, not as granules, but as ill defined submicroscopic concentrates which blended imperceptibly into the homogeneous matrix of the vacuolar walls. Objections to the use of stains for improving contrast conditions in electron microscopy of tissues are discussed, and it is concluded that the reagents do not necessarily produce the observed increases in contrast by selectively stabilizing certain structures. The concept of microsomes as pre-existing distinct morphological entities in intact (unhomogenized) cells is thought to be inconsistent with the distribution of basophile substances in frozen-dried liver.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号