大鼠和小鼠精子发生过程中线粒体结构增殖和分布的研究

本研究采用超薄切片和冷冻蚀刻复型膜技术,制备大鼠和小鼠曲细精管样品,在透射电镜下观察各种生精细胞内线粒体的形态、数量、分布和膜结构。线粒体的增殖、发育和分布,与精子发生过程密切配合,表现为:1.线粒体的数量以休止期精原细胞最少;初级精母细胞线粒体自身分裂,迅速增殖,数量增加;精子细胞中数量比较恒定。2.线粒体的分布在精原细胞中随机分布,精母细胞内集中成群,高尔基期精子细胞线粒体分散在高尔基复合体附近或质膜下,头帽期、顶体期移至尾侧,成熟精子线粒体规则地排列在尾部中段密纤维外。3.线粒体的形态和发一育,在精原细胞线粒体为圆形或椭圆形,嵴平行,精母细胞线粒体延伸成杆状,并分裂形成新线粒体。新形成的线粒体缺少嵴,线粒体基质电子密度很低,成熟精子的线粒体嵴不规则。线粒体膜为三夹层结构,蛋白颗粒主要分布在外膜,内嵴蛋白颗粒很少,或缺少蛋白颗粒。     

微波照射对兔精子形成影响的电子显微镜观察

本研究用微波(2450 MHz)照射兔阴囊及睾丸,使阴囊皮肤温度升至41～42℃,维持20分钟。用电镜观察照射后30分钟至4个月之间不同时间阶段对精子形成的影响。30～60分钟,高尔基期、头帽期、顶体期及成熟期的精子细胞已出现形态学的改变。30～60天后退变的成熟期精子细胞增多。3～4个月后精子细胞一般恢复正常。各期精子细胞对微波都很敏感。损伤改变主要见于顶体、顶体下间隙、核、尾部线粒体鞘、纤维鞘、外致密纤维及顶体后致密膜。早期精子细胞的平滑型内质网和核膜间隙扩大及空泡化也经常见到。本文所见微波致精子细胞的超微结构改变,在许多方面与超声及实验性隐睾所致的改变相似。     

大鼠精子发生和形成过程中溶酶体超微结构和CMPase的细胞化学变化

通过超微结构及胞嘧啶单核苷酸酶（ｃｙｔｉｄｉｎｅ ｍｏｎｏｐｈｏｓｐｈａｔａｓｅ，ＣＭＰａｓｅ）细胞化学方法研究大鼠精子发生和形成过程中溶酶体的动态变化。结果表明：精原细胞中只有极少的溶酶体，精母细胞中溶酶体明显增多；高尔基期精子细胞中出现前顶体泡，高密度多泡体和其他形态的溶酶体，它们呈现ＣＭＰａｓｅ阳性。头帽期时精子细胞顶体系统不断扩大，高密度多泡体等溶酶体已转移至形成中的精子尾附近，并一直停留     

多疣壁虎精子超微结构

目的:研究多疣壁虎精子超微结构,探讨爬行类精子进化规律.方法:用光镜及透射电镜观察多疣壁虎的精子.结果:多疣壁虎精子总长度约65～75 μm,头部弯曲长约27～30μm,尾部约 40～47 μm.用透射电镜观察多疣壁虎精于超微结构,可见其精子具有以下特点:顶体复合体由顶体帽、顶体下问隙、穿孔器、中央管、顶体下核帽5个部分组成;中段的轴丝复合体与线粒体鞘之间具有微管鞘(microtubule sheath)结构,线粒体鞘向后延伸包围主段,形成终环后隐窝结构;主段具有厚的圆筒状纤维鞘.结论:多疣壁虎精子超微结构比较研究显示爬行类精子具有种的特异性,提示了爬行类可能为多源起源.     

猕猴精子获能和顶体反应过程中Ca~（2＋）和Ca~（2＋）－ATPase定位及咖啡因和dbcAMP对顶体反应的影响

用焦锑酸钾原位沉淀法和枸橼酸铅捕获法研究了猕猴精子获能和顶体反应过程中的Ｃａ~（２＋）分布和Ｃａ~（２＋）－ＡＴＰａｓｅ活性。获能前精子头部Ｃａ~（２＋）主要分布于顶体区质膜内外、顶体外膜和顶体内膜内侧，尾部Ｃａ~（２＋）主要分布于线粒体基质，在质膜、致密纤维和轴丝处也有一定分布，在获能过程中Ｃａ~（２＋）进入精子内部，并在头部结合于顶体区质膜内侧和顶体外膜外侧。顶体反应时Ｃａ~（２＋）结合于顶体内膜外侧和由顶体外膜囊泡化形成的囊泡内外，另外还有一些Ｃａ~（２＋）分散存在于顶体内容物中。在ｐＨ９．０条件下，头部Ｃａ~（２＋）－ＡＴＰａｓｅ活性存在于顶体外膜外侧和顶体区质膜外侧，顶体后区质膜无此酶活性。尾部Ｃａ~（２＋）－ＡＴＰａｓｅ存在于质膜、线粒体膜及致密纤维和轴丝处。各处的Ｃａ~（２＋）－ＡＴＰａｓｅ活性在获能和顶体反应过程中一直存在。咖啡因和ｄｂｃＡＭＰ可提高精子运动能力，前者还可显著增加顶体反应率。     

金黄地鼠精子发生及附睾成熟过程中Ca~（2＋）的分布规律

应用焦锑酸钾原位沉淀法对金黄地鼠精子发生及附睾成熟过程中Ｃａ２＋的分布变化规律进行了系统的研究。在睾丸的曲细精管中，支持细胞和生精细胞的细胞核和细胞质有钙沉淀颗粒分布。在支持细胞、精原细胞、精母细胞、高尔基体期和顶体期精子细胞的胞质中钙沉淀主要分布于线粒体和内质网。支持细胞核仁的无定形部分、核仁相随染色质和核质中有大量的钙沉淀颗粒。在精原细胞、精母细胞、高尔基体期的精子细胞核中钙沉淀主要分布于浓缩的染色质周围及其内部，而分散的染色质中则少见钙沉淀。在顶体期的精子细胞核内钙沉淀主要分布于核膜上，核质中偶见Ｃａ２＋沉淀。成熟期的精子细胞钙沉淀颗粒分布于顶体外膜和顶体内膜的内侧，顶体内膜上有钙沉淀集中分布。在附睾中钙沉淀分布于精子顶体区的质膜内外两侧和顶体外膜外侧，精子尾部线粒体外膜和基质中也有钙沉淀分布。     

猕猴精子获能和顶体反应过程中Ca^2＋和Ca^2＋—ATPase定位及咖啡因…

用焦锑酸钾原位沉淀法和枸橼酸铅捕获研究了猕猴精子获能和顶体反应过程中的Ｃａ＾２＋分布和Ｃａ＾２＋－ＡＴＰａｓｅ活性。获能前精子头部Ｃａ＾２＋主要分布于顶体区质膜内外、顶体外膜和顶体内膜内侧，尾部Ｃａ＾２＋主要分布于线粒体基质，在质膜、致密纤维和轴丝处也有一定分布。在获能过程中Ｃａ＾２＋进入精子内部，并在头部结合于顶体区质膜内侧和顶体外膜外侧。顶体反应时Ｃａ＾２＋结合于顶体内膜外侧和由顶体外膜囊泡化     

北草蜥精子形成的超微结构研究

目的研究北草蜥的精子形成过程。方法以2．5％戊二醛和1％锇酸双重固定,常规制作石蜡切片和超薄切片,光镜和透射电镜观察。结果北草蜥精子形成过程主要有核逐渐延长、染色质浓缩、顶体形成、线粒体逐步发达与融合、细胞质消除与鞭毛形成等。可分为4个时期：时期Ⅰ,精子细胞前顶体囊泡移至核膜时,核膜凹陷形成封闭的顶体囊泡,囊泡底部靠近核膜有一电子致密的顶体颗粒,在1个薄层有颗粒的胞质中形成顶体下颗粒,将顶体颗粒和核膜连接起来;时期Ⅱ,精子细胞顶体囊泡扁平,细胞核延长,染色质浓缩成短丝状的染色质纤维;时期Ⅲ,精子细胞核进一步延长,染色质纤维变粗变长,并沿核纵轴方向有序排列,近端中心粒及尾部开始出现;时期Ⅳ,Sertoli细胞质内纵行微管出现,至精子释放前消失,精子细胞顶体发育完全,终环形成,核内染色质纤维浓缩至最大限度,呈高电子致密度的均质状态。结论北草蜥精子形成过程中细胞核及细胞器的超微结构变化在有鳞类蜥蜴分类上具有重要意义。     

转化细胞内质网分布—可能的蛋白出胞新模式

目的 :探讨细胞诱发转化中内质网的生物学特性。方法 :利用改进的整装培养细胞内质网技术对转化状态下的细胞内质网及固定细胞内质网超微结构进行观察。结果 :显示细胞的内质网由正常的网状转变为链锁状 ,发育不良 ,且在伪足及细胞边缘可见内质网结构及其独支盲端。结论 :从新的角度证实癌变细胞的内质网生物学特点及癌变细胞蛋白质运输经由内质网直接出胞的可能性     

山羊卵子受精及原核期胚胞质成分的微细结构研究

本研究用光镜和电镜观察到山羊卵子受精15～16小时后,大部分处在原核期。受精卵透明带表面和外层内,有许多多余精子。透明带表面的精子,有的正在发生顶体反应,穿入透明带的精子,在透明带表面上留有顶体反应小泡。穿入透明带的多余精子均滞留在外层,无一进入内层或卵周隙。受精卵皮质颗粒排放较彻底,有皮质颗粒残留处质膜上微绒毛较少。原核期合子皮质区分布着许多成群的带帽线粒体和一些滑面内质网小泡、卵黄泡和脂滴。原核周围聚集着发达的高尔基复合体、滑面内质网、线粒体和环孔板。文中讨论了受精卵这些形态变化的意义。     

Evolution of the endoplasmic reticulum during spermiogenesis of the rooster: An electron microscopic study

The endoplasmic reticulum (ER) of rooster's spermatids was analyzed during spermiogenesis, which was subdivided into eight distinct steps on the basis of changes observed with the electron microscope in the nucleus, acrosome-perforatorium system, manchette, and flagellum. In steps 1 and 2, spermatids' ER cisternae presented the following specializations: (1) A loose network of tubular cisternae was distributed throughout the cytoplasm. (2) Six to eight tight networks of anastomosed tubular cisternae parallel to each other were closely stacked to form a discoid body (1.5–2.5 μm in diameter and 0.5–0.8-μm thick) in which spheroidal vesicles (0.4 μm in diameter) were inserted. Close to and connected with this body, called the alveolar body, there was a stack of annulate lamellae. (3) Large, flattened ER cisternae were seen singly or in piles of two or three running parallel to the nuclear surface. (4) A collection of tubular ER cisternae faced plaques of thickened plasma membranes. These elements of the ER system appear continuous with each other. During steps 3–5 of spermiogenesis, no modification of the alveolar body-annulate lamellae complex was noted; the large flattened ER cisternae disappeared, however, and the broad network of tubular cisternae developed markedly. During steps 6 and 7, the latter network of tubular cisternae fragmented into vesicles that swelled to give a vacuolated appearance to the cytoplasm. The alveolar body-annulate lamellae complex remained visible until late step 7, when it disintegrated just before spermiation. Thus the system of ER cisternae underwent marked structural modifications during spermiogenesis.     

Evolution of the endoplasmic reticulum during rat spermiogenesis

The endoplasmic reticulum (ER) was stained selectively by a sequence of uranyl acetate, lead and copper citrate, according to the method of Thiéry and Rambourg ('76), and then investigated in 0.5 to 2.0-μm-thick sections with the transmission electron microscope. Examination of photographic stereopairs allowed a three-dimensional visualization of the ER at various steps of spermiogenesis. During the Golgi and cap phases of spermiogenesis (steps 1–7, classification of Leblond and Clermont, '52a), the ER is distributed throughout the cytoplasm as a three-dimensional network of spherical and tubular cisternae connected by narrow tubules. In addition, a close network of tubular cisternae is located along the convex surface of the Golgi apparatus and lines the plasma membrane. Where the cell membrane joins that of another spermatid to form an intercellular bridge, this network extends across the bridge. During the acrosome phase (steps 8–14), the cytoplasm contains an abundant ER that shows the following modifications: (A) Along the inside and outside of the caudal tube the cisternae form long tubes or plates which run adjacent and parallel to the microtubules. These cisternae are connected by delicate lateral anastomoses; (B) Along the flagellum the ER forms a “fenestrated sleeve” made up of a close network of tubular cisternae; (C) Similar networks are organized as “fenestrated spherules” enclosing large vesicles seen throughout the cytoplasm; (D) At a short distance from the flagellum, the ER cisternae are continuous with a stack of annulate lamellae and an aggregate of radially arranged collapsed cisternae called the “radial body”. During the last or maturation phase (steps 15–19), the ER regresses. Thus, during the final steps in the formation of the flagellum, the ER network fragments and then most of the cisternae disappear from the cytoplasm. The “radial body” is the last element of the ER to be dissolved. Thus the ER undergoes extensive structural modifications during spermiogenesis, suggesting an active contribution of this organelle to the differentiation of the spermatid into a spermatozoon.     

Dynamic changes in Sertoli cell processes invading spermatid cytoplasm during mouse spermiogenesis

Studies using thick sections stained by ATPase cytochemistry and scanning electron microscopy were carried out to determine three-dimensional ultrastructural alterations in Sertoli cell processes invading neighboring spermatids during mouse spermiogenesis. Sertoli cell processes start invading spermatid cytoplasm at the acrosomal phase of development and undergo considerable change at the maturation phase of development. At step 14, these processes elongate and begin to branch in the spermatid cytoplasm, and by step 15, they extend in various directions to form a complex of canals that the authors have designated the canal complex. The present observations also clarify that the complicated canal complex undergoes regional modification. At the late stages of maturation, the endoplasmic reticulum has gathered with other cell organelles to form aggregates of endoplasmic reticulum in the vicinity of which invading Sertoli cell processes extensively ramify further into thin tubules that intertwine with each other to form a region of thin tubules. In thin sections, each such region was a complex, consisting of small vesicles and endoplasmic reticulum, and corresponded to what has been defined as a mixed body by Morales and Clermont (Anat. Rec., 203:233-244, 1982). During the course of the formation of the region, the invading Sertoli cell processes are continuous at all times with the cell body of the surrounding Sertoli cell.     

Alterations in the endoplasmic reticulum and golgi complex of intestinal epithelial cells during fat absorption and after termination of this process: A morphological and morphometric study

Earlier investigations of intestinal fat-absorption have stressed the importance of continued protein synthesis to provide membranes which are utilized for the intracellular transport of resynthesized lipid. The resulting membranes, when incorporated into the endoplasmic reticulum (ER) and Golgi complex, serve as vehicles for the movement of fat within the cell and for its release to the extracellular space. In the current study, attention was focused on the morphological changes in the ER and Golgi complex both during fat absorption and at successive time intervals after fat-absorption termination. Morphological interpretations were confirmed by morphometric analysis. This investigation supports the interpretation that during fat absorption, membrane synthesis by the rough endoplasmic reticulum (RER) is insufficient to accomodate membrane utilization and intraconversion, resulting in a decrease of both ER and Golgi complex components. However, following fat-absorption termination, the cell is able to replace previously depleted components of the ER and Golgi complex and regain the full membrane complement of the fasted state. Replenishment of cellular membranes is postulated as resulting from a continued synthesis of new membranes by the RER which eventually exceeds membrane utilized during lipid transport.     

细胞增殖过程中整装培养细胞内质网膜系统的组建特点

利用高锰酸钾技术，通过透射电镜观察了经同步化处理的整装培养的正常细胞在细胞周期各时相中内质网膜系统的结构变化，发现细胞的内质网膜系统在细胞的生长发育过程中由直径较粗、稀疏而分散的网状结构，逐渐组建成直径较细、致密分布的连续网状结构     

Ca2+与内质网途径的细胞凋亡

细胞Ca2+稳态的维持主要是通过内质网进行的，Ca2+在细胞内的活动多与内质网有关，胞内\[Ca2+\]的变化可以引起内质网应激，而过度的内质网应激则会导致细胞的凋亡。由于内质网和线粒体在细胞内空间结构上的接近，内质网释放的Ca2+又会引起线粒体途径的凋亡。一些内质网相关的因素也参与Ca2+所引起的细胞内质网途径的凋亡。     

Ischemia induces endoplasmic reticulum stress and cell apoptosis in human brain

In animal models, endoplasmic reticulum (ER) stress and apoptosis take place around cerebral infarction areas during ischemia, which presumably protect tissues from necroses-induced injury as well as promote cells toward death. We examined whether these pathological changes, especially temporal occurrence, were present in patients who suffered from cerebral ischemia. The studies by immunohistochemistry show that ER chaperone glucose-regulated protein (GRP78) and caspase-9 elevate around infarction areas. The experiments by terminal deoxynucleotidy transferase-mediated 2′-deoxyuridine 5′-triphosphate-biotin nick-end labeling (TUNEL) illustrate that TUNEL-positive cells are higher around infarction tissues than controls. Moreover, GRP78, caspase-9 and TUNEL cells emerge one after another during ischemia. In conclusion, ER stress, apoptosis initiation and DNA fragment develop sequentially in ischemic human brain. ER stress during excessive ischemia stimulates apoptotic cell death beyond activating a defense for nerve cells being away from injury.     

内质网应激反应基因表达调控的多样性

内质网通过激活未折叠蛋白反应(unfolded protein response,UPR),包括蛋白合成暂停、内质网分子伴侣和折叠酶等蛋白表达上调、诱导内质网相关性降解(ER-associated degradation,ERAD),以至细胞功能不能恢复,最后诱导内质网相关性细胞凋亡,清除受损细胞,保护机体生存。所有这些内质网相关反应都是各种应激信号刺激内质网,引起多种内质网应激基因表达的结果。转录、翻译以及翻译后加工各个环节对内质网应激时基因的表达产生调控,且方式各不相同。     

Ultrastructural changes in cells of the inner enamel epithelium, stratum intermedium and reticulum stellatum in the enamel organ of the upper incisor of the Wistar rat at different phases of amelogenesis]

An electronmicroscopical study of the enamel organ of the upper incisors germs of Wistar rats was performed to analyse the ultrastructural features of the cells of the inner epithelium, the intermediate layer and the stellate reticulum, during preimary, young, transitional and mineralized enamel phases of amelogenesis. So, it was observed that the mitochondria in the ameloblasts are ovoid before the beginning of the enamel matrix formation and in the primary and young enamel phases. However, in the transitional and mineralized phases, these organelles are long and tortuous and some are characterized by a compact structure. In the cells of intermediate layer and stellate reticulum, the mitochondria are ovoid until the beginning of the mineralized phase. At the ending of this phase, these organelles are very long and present irregular form; many of them show also a compact structure. The "zonula adhaerens" could be observed only in the ameloblasts of the primary and young enamel phase. The cytoplasm of ameloblasts, during primary and young enamel phases is characterized by an abundance of free ribosomes and a branular endoplasmic reticulum; but during transitional and mineralized enamel phases, the cytoplasm of these cells shows little granular endoplasmic reticulum and free ribosomes, but ehe agranular endoplasmic reticulum is present. The granular endoplasmic reticulum and free ribosomes are abundant in the cells of the intermediate layer and stellate reticulum at the ending of the young enamel phase, in the transitional enamel phase and in the beginning of the minieralized phase. During different phases of amelogenesis, in the three above referred layers of the enamel organ, were also studied the features of the Golgi apparatus the presence and topographic distribution of the pigment granules, as well as the lysosomes, desmosomes and the tonophibriles.