人颈淋巴结淋巴细胞酶超微结构定位与活性研究

应用电镜酶细胞化学方法研究了人颈淋巴结淋巴细胞ＡＴＰ酶、Ｇ－６－Ｐ酶、５’－Ｎａｓｅ的定位与活性。结果：ＡＴＰ酶主要定位在淋巴细胞膜及内质网、线粒体等膜相结构。Ｇ－６－Ｐ酶主要定位在内质网、线粒体等膜相结构。５’－Ｎａｓｅ主要定位在细胞膜外表面,在内质网与线粒体股外表面也可见此酶反应颗粒。３种酶定位准确、颗粒清晰,酶反应特异性强。结果提示应用此法可以检测以上酶活性,对判定机体免疫状态、对临床诊断与治疗具有一定意义。     

THE FINE STRUCTURE OF NEURONS

1. Thin sections of representative neurons from intramural, sympathetic and dorsal root ganglia, medulla oblongata, and cerebellar cortex were studied with the aid of the electron microscope. 2. The Nissl substance of these neurons consists of masses of endoplasmic reticulum showing various degrees of orientation; upon and between the cisternae, tubules, and vesicles of the reticulum lie clusters of punctate granules, 10 to 30 mµ in diameter. 3. A second system of membranes can be distinguished from the endoplasmic reticulum of the Nissl bodies by shallower and more tightly packed cisternae and by absence of granules. Intermediate forms between the two membranous systems have been found. 4. The cytoplasm between Nissl bodies contains numerous mitochondria, rounded lipid inclusions, and fine filaments.     

Mechanisms of protein yolk synthesis and deposition in crustacean oocytes

Summary Electron microscope studies on the oocytes of several crustacean species demonstrate that the protein yolk arises within vesicular and lamellar forms of the rough-surfaced endoplasmic reticulum. The vesicular form of the endoplasmic reticulum may have its origin from a blebbing process of the outer layer of the nuclear envelope. Disc-shaped granules, representing precursor elements of the yolk granules, appear within the vesicular and lamellar profiles of endoplasmic reticulum. Autoradiographic results suggest that the ribosomes attached to the endoplasmic reticulum take part in the biosynthesis of yolk proteins. Numerous disc-shaped granules accumulate within the cisternae of the endoplasmic reticulum, but eventually they undergo a transformation into a finely granular yolk granule. Thus, both the origin and growth of protein yolk granules occur within membranes constituting the endoplasmic reticulum. The results provide evidence that intra-ooplasmic synthesis of yolk protein occurs in these oocytes.This investigation was supported by research grants (HD-00699; GM-09229) and a Career Development Award (GM-11,524) from the National Institutes of Health, U.S. Public Health Service.     

The smooth endoplasmic reticulum in neurohypophysial axons of the rat: Possible involvement in transport,storage and release of neurosecretory material

Summary The intra-axonal organization of the smooth endoplasmic reticulum was studied in the neurohypophysis of rats during and after water deprivation. Parallel to conventional electron microscopy, the material was treated with a double impregnation staining technique specifically designed to contrast the intracellular membranous system. In conventionally stained ultrathin sections from severely dehydrated rats most axons appeared to be free of membranous organelles, whereas corresponding axons treated with the double-impregnation technique generally exhibited a highly developed system of smooth endoplasmic reticulum. In axonal endings, both techniques revealed a profusion of microvesicles in intimate relationship with tubular elements of the smooth endoplasmic reticulum. In short-term (12 h) rehydrated rats, a similarly developed system of smooth endoplasmic reticulum was still observed at all axonal levels with both procedures. After 24 to 48 h of rehydration the tubules of the smooth endoplasmic reticulum exhibited, in double impregnated material, numerous dilatations which resembled the adjacent neurosecretory granules. In conventionally stained ultrathin sections, an accumulation of electron dense material occurred within tubules of the smooth endoplasmic reticulum in the more proximal axonal segments, while in the more terminal segments, which contained numerous elongated granules, membrane continuity was frequently observed between newly formed granules and the smooth endoplasmic reticulum. After 7 days of rehydration the general pattern of the axonal smooth endoplasmic reticulum was comparable to that in untreated rats. These results are discussed in the light of a suggested involvement of the axonal smooth endoplasmic reticulum in the non-granular transport of neurosecretory material in connection with (1) storage in distally formed granules, and (2) release via microvesicles. Acknowledgements: The authors wish to express their gratitude to Mrs. M. Balmefrézol for her skillful technical assistance     

Ultrastructural and Morphometric Observations of Cortical Endoplasmic Reticulum in Arbacia,Spisula and Mouse Eggs*

Results of morphometric investigations indicate that Arbacia eggs possess a network of cortical endoplasmic reticulum equal in volume and surface area to that within the subcortex. The cortical endoplasmic reticulum surrounds individual cortical granules and forms associations with the plasma membrane reminiscent of junctions shared by the sarcolemma and sarcoplasmic reticulum. Mouse eggs, which also exhibit a cortical granule reaction, possess endoplasmic reticulum that is associated with cortical granules and the plasmalemma. The same relative volume of cortical endoplasmic reticulum is present in mouse eggs as in Arbacia. Significantly less cortical endoplasmic reticulum is present in Spisula eggs which do not undergo cortical granule discharge upon activation. These observations are discussed in light of the hypothesis that the cortical endoplasmic reticulum transduces the interaction of the gametes into an intracellular calcium release which initiates the cortical granule reaction and the activation of development.     

CRYSTALLINE INCLUSIONS IN THE NUCLEAR ENVELOPE AND GRANULAR ENDOPLASMIC RETICULUM OF THE FISH SPINAL CORD

Crystalline inclusions were found in the nuclear envelope and granular endoplasmic reticulum of spinal cord oligodendroglia of the common guppy (Poecilia reticulata) and the lungfish (Polypterus enlicheri). A considerably increased incidence of these inclusions was noted in guppies with congenital and hereditary (sex-linked, recessive) lordosis. Identical crystalline inclusions were observed in protoplasmic and fibrous astrocytes, ependymal cells, and capillary endothelial cells of the spinal cord of the lordotic fish. The oligodendroglia in these fish also revealed a prominent alteration of the endoplasmic reticulum and Golgi apparatus, with the accumulation of dense (secretion?) granules and large amounts of electron-opaque material in markedly dilated sacs of the endoplasmic reticulum. The authors postulate that this alteration is caused by a genetic defect in the control mechanism governing the elaboration of this material in the lordotic guppy, with subsequent stasis and crystallization of this material.     

Lipid inclusions in cells and their changes during the desiccation and reactivation of yeast organisms

The formation of lipid granules in Saccharomyces cerevisiae cells was shown to begin in the exponential phase of the culture growth and to be associated with the activity of the endoplasmic reticulum. Lipid granules can be formed (1) when the endoplasmic reticulum cisterns extend and (2) when the endoplasmic reticulum membranes separate relatively small regions of the cell cytoplasm. Yeast cells contain spherosomes which differ in their structure. Lipid granules merge together upon dehydration of yeast cells. The authors discuss possible participation of these granules in the reparation of damages of the intracellular membranes.     

大鼠粒细胞内质网的电镜细胞化学反应

本实验用电镜细胞化学方法观察了大鼠骨髓粒细胞发育过程中内质网的髓过氧化物酶(MPO)反应和葡萄糖-6-磷酸酶(G-6-P)反??应。结果表明:MPO除定位于内质网、核膜,还出现在高尔基体和颗粒,它是粒细胞内质网的合成产物。G-6-P只在内质网、核膜中出现,它是内质网膜的结构成分。MPO反应的超微结构定位随粒细胞发育而变,利用这种变化作标志可以划分不同发育阶段的粒细胞;G-6-P反应定位不随发育而变,但反应强度与内质网的多寡、功能状态相对应。实验还表明核膜与内质网在结构、功能上的一致性;尤其在成熟粒细胞内质网很少的情况下,核膜可能代替了内质网的功能。     

PEROXISOMES IN INNER ADRENOCORTICAL CELLS OF FETAL AND ADULT GUINEA PIGS

Abundant membrane-bounded granules, 0.1–0.45 µm in diameter, occur among the elements of the smooth-surfaced endoplasmic reticulum in zona fasciculata and zona reticularis adrenocortical cells of guinea pigs. Acid phosphatase cannot be cytochemically demonstrated in them, and they are therefore distinct from lysosomes. Incubation in medium containing 3,3'-diaminobenzidine results in dense staining of the granules, identifying them as peroxisomes. These small peroxisomes increase in number as fetal adrenocortical cells differentiate, and they appear to arise from dilated regions of endoplasmic reticulum. They maintain interconnections with the smooth endoplasmic reticulum and with one another.     

AN ELECTRON MICROSCOPE STUDY OF THE GLAND CELLS OF THE MINK ENDOMETRIUM

Portions of mink endometrium in delayed implantation, early postimplantation, and pseudo pregnancy were fixed in buffered osmium tetroxide with sucrose, or potassium permanganate. After rapid dehydration the portions of endometrium were embedded in either methacrylate or epoxy resin. Examination of the cells from the body of the glands of the endometrium of delayed implantation revealed the presence of prominent terminal bars, numerous secretion granules, and membrane discs in the apical region of the cell. In the supranuclear and infranuclear regions, mildly dilated cisternae of the endoplasmic reticulum were present, and in many cells unusually large mitochondria were seen. Numerous changes were noted in the gland cells of the post implantation stage. The endoplasmic reticulum in the basal region was extensively dilated, and the nuclei were situated more centrally. Giant mitochondria were no longer present. The large secretion granules were not present, but smaller granules were seen, especially in the Golgi region. Some of the Golgi cisternae were dilated and the pattern of parallel membranes was consequently less distinct. It is suggested that gland cells in the postimplantation and pseudopregnancy stages exhibit evidence of greater secretory activity than those in the delayed implantation stage.     

AN ELECTRON MICROSCOPE STUDY OF MATURE AND DIFFERENTIATING PANETH CELLS IN THE RAT, ESPECIALLY OF THEIR ENDOPLASMIC RETICULUM AND LYSOSOMES

In an electron microsope study, the morphology of mature Paneth cells from the small intestine of adult rats is compared with that of differentiating Paneth cells from young rats 2 to 4 weeks old. All mature cells exhibit a marked polarity similar to that of other exocrine gland cells and contain a well developed endoplasmic reticulum, an elaborate Golgi complex, and numerous large secretory granules; they also possess an abundance of lysosomes. The most conspicuous occurrence in the process of differentiation is the development of the endoplasmic reticulum. The most immature Paneth cells possess an endoplasmic reticulum of the vesicular type, which, during maturation, is replaced by the characteristic lamellated ergastoplasm of the mature cell. At a certain stage of differentiation the cavities of the developing cisternae show numerous communications with the perinuclear space, suggesting an outgrowth of the ergastoplasm from the nuclear envelope. Furthermore, the cavities and the perinuclear space at this particular stage contain a material which shows a remarkable intrinsic periodicity. An identical periodicity was exhibited by material contained in Golgi cisternae and secretory granules. Lysosomes are also present in the differentiating cells.     

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。     

ELECTRON MICROSCOPY OF THE TISSUE MAST CELL

Electron microscopy was carried out on sections through tissue mast cells from the peritoneal fluid of rats and hamsters, either untreated, x-irradiated, or injected with toluidine blue, protamine sulfate, or stilbamidine. Mast cells from untreated animals have large nuclei and are filled with densely packed, cytoplasmic granules. The latter possess a distinct boundary and an internal structure which is reticular or vacuolar in nature. Between the granules are found elongate mitochondria and endoplasmic reticulum. Mitochondria often appear also in groups in granule-free areas adjacent to the nucleus. Nuclear and cell membranes of an apparent double nature are found. After treatment with toluidine blue, protamine sulfate, and stilbamidine the granules are surrounded by clear areas and are widely separated from one another; the endoplasmic reticulum is more conspicuous. The internal structure of the granule is unchanged. In the mast cells from x-irradiated animals there is an apparent coalescence of granules which is attented by a loss of intragranular structure. The findings are discussed in relation to other work on the structure and function of mast cells.     

Self-organization of endoplasmic reticulum aggregates in cells with overexpression of nucleoporin POM121

The nuclear pore complexes are complex protein structures located in the nuclear envelope, where they control the nuclear-cytoplasmic transport, and inside the stacks of endoplasmic reticulum cisternae, annulate lamellae. After overexpression of some nucleoporins, numerous granules are visible in the cytoplasm. According to the published data, these granules are the annulate lamellae. In the current paper, the structural organization of POM121-containing granules was analyzed using correlative light and electron microscopy. The ultrastructural study demonstrates that POM121-containing granules are not annulate lamellae but aggregates of endoplasmic reticulum membranes. Thus, overexpressed POM121 is not able to induce the annulate lamella formation. The mechanisms of self-organization of non-functional structures (such as the aggregates of endoplasmic reticulum membranes described here) and possible involvement of these mechanisms in the formation of cellular structures are discussed.     

A STUDY OF THE FINE STRUCTURE OF THE EPIDERMIS OF RANA PIPIENS

The epidermis of adult Rana pipiens has been studied by electron microscopy and histological and histochemical methods. It was found that the epidermis is engaged in the production of both keratin and mucus. The basal cells are mainly filled with tonofilaments, whereas the cells located in the mid-portion of the epidermis contain both tonofilaments and mucous granules. Golgi vesicles and endoplasmic reticulum are found in relative abundance in the mucus-producing cells and seem to be involved in the production of mucous granules. The mucus seen was partly retained within the cells and partly secreted into the intercellular spaces. The outermost keratinized cells contain mainly filaments and a few remnants of cell constituents.     

Stereological study of endoplasmic reticulum, Golgi complex and secretory granules in the B-cells of normal and alloxan-treated mice.

Different B-cell organelles (lamellar and vesicular endoplasmic reticulum, Golgi complex, whole secretory granules and secretory granule cores) were studied stereologically in pancreatic islets from control mice and mice killed 10 or 60 min following alloxan injection. Ten min following alloxan a significant decrease was observed in the volume, surface and numerical densities of whole secretory granules and their cores, and a significant increase was found in the volume and surface densities of vesicular endoplasmic reticulum. At the 60 min observation time, a significant decrease was seen in the volume density of lamellar endoplasmic reticulum and Golgi complex, and in the volume, surface and numerical densities of whole secretory granules and their cores, and a significant increase was observed in the volume and surface densities of vesicular endoplasmic reticulum, and in the mean values for volume and surface of whole secretory granules and their cores. The stereological data indicate swelling of endoplasmic reticulum, decreased Golgi area, and decreased number and total volume and surface of secretory granules during the first hour after alloxan administration to mice. The observations may be consistent with inhibited insulin synthesis.     

Pancreatic damage induced by injecting a large dose of arginine

Male Wistar rats were injected intraperitoneally with a large dose of arginine (500 mg/100 g body weight) and were sacrificed 24, 48 and 72 h later. Pancreatic tissue was examined by electron microscopy to study the resulting process of degeneration. Degeneration started with disorganization of the rough endoplasmic reticulum into whorls with a concomitant decrease in the numbers of zymogen granules. The main changes in acinar cells after 24 h were partial distension of the endoplasmic reticulum, whorls of agranular membranes encircling zymogen granules and perinuclear vacuoles. At this time large sequestered areas in the cytoplasm contained disarranged rough endoplasmic reticulum and degraded zymogen granules. The mitochondria showed only slight changes. After 48 h, dissociation and necrosis of acinar cells were noted. Subsequently, the necrotic cells were replaced by interstitial tissue composed of leucocytes and fibroblasts. It was concluded that a large dose of arginine is toxic to the rat pancreas when injected intraperitoneally. The early morphological changes of the acinar cells may be related to metabolic alterations associated with the endoplasmic reticulum. The disorganization of the endoplasmic reticulum and the reduced number of zymogen granules may indicate disturbance of protein synthesis. The focal sequestration and degradation of the cytoplasm seemed to represent changes of the acinar cells associated with removal of damaged organelles.     

The Ultrastructure of Circulating Hemolymph Cells of the Marine Snail Cerithidea californica (Gastropoda: Prosobranchiata)

Two morphologically distinct blood cell-types, the granulocyte and hyalinocyte, are found in the hemolymph circulation of the marine prosobranch Cerithidea californica. Granulocytes, measuring 12.7 µ (9.0–15.0 µ) in diameter, possess well-defined ectoplasmic and endoplasmic regions of the cytoplasm, granules of moderate to heavy electron density, tubular rough endoplasmic reticulum (RER), short vesicles of smooth endoplasmic reticulum (SER), and a large cytoplasm to nucleus ratio. Two morphological variants of this cell-type are distinguished depending upon the presence or absence of dense granules or RER. Hyalinocytes, measuring 5.3 µ (4.0–8.0 µ) in diameter, are distinguished from gran ulocytes by possessing a smaller cytoplasm to nucleus ratio and a general lack of dense cytoplasmic granules and SER.     

Light and electron microscopic studies of crayfish hemocytes

Using light and electron microscopy, three hemocyte types are described in the hemolymph of the crayfish. The coagulocyte comprises 65% of the total hemocyte number and contains medium-sized cytoplasmic granules, abundant dilated rough endoplasmic reticulum, and a highly developed Golgi complex. It rapidly undergoes cytolysis in vitro and participates in coagulation by releasing the contents of its granules to the hemolymph. The granulocyte comprises 31% of the total hemocyte number and is capable of phagocytosis. It contains large, irregularly shaped cytoplasmic granules, a moderately developed Golgi complex, and moderate amounts of non-dilated rough endoplasmic reticulum. During coagulation in vitro, the cell attaches and spreads onto the substratum; this is followed by a slow intracellular granule breakdown and cytolysis. The amebocyte comprises 4% of the total hemocyte number and it is also capable of phagocytosis. It possesses small cytoplasmic granules, many vacuoles, a moderately developed Golgi complex, and large amounts of smooth endoplasmic reticulum. It is distinguished from the other two cell types by being stable and motile in vitro.     

Calreticulin: not just another calcium-binding protein

In this paper we review some of the rapidly expanding information about calreticulin, a Ca²⁺-binding/storage protein of the endoplasmic reticulum. The emphasis is placed on the structure and function of calreticulin. We believe that calreticulin is a multifunctional Ca²⁺-binding protein and that distinct functional properties of the protein may be localized to each of the three structural domains of calreticulin. Most evidence indicates that calreticulin is a resident endoplasmic reticulum protein. However, it can also be found outside of the endoplasmic reticulum compartment, i.e. in the nuclear envelope, in the nucleus, in the cytotoxic granules in T-lymphocytes and in acrosomal vesicles of sperm cells. The evidence reviewed here clearly suggests that calreticulin has other functions in addition to its role as a Ca²⁺ storage protein in the endoplasmic reticulum.Abbreviations SR sarcoplasmic reticulum - ER endoplasmic reticulum