Confronting cisternae in pituitary gland thyrotrophs of congenitally hypothyroid mice

Confronting cisternae were found in pituitary thyrotrophs of congenitally hypothyroid mice. These confronting cisternae rapidly reverted back to ordinary rough endoplasmic reticulum following thyroxine administration. Confronting cisternae were not observed in the thyrotrophs of euthyroid control mice. Our results strongly suggest that confronting cisternae are a peculiar form of rough endoplasmic reticulum which appears under certain conditions of enhanced cellular metabolism.     

Enzyme cytochemistry of the alveolar sacs and golgian-like cisternae in the ciliate Ichthyophthirius multifiliis

In the cell cortex of the parasitic ciliate Ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. The thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. Using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs of trophozoites. In the endoplasmic reticulum acid phosphatase activity was not detected and only very small amounts of thiamine pyrophosphatase and nucleoside diphosphatase reaction product were observed. After exit from the host, a reduction in acid phosphatase activity was evident in the alveolar sacs. At theront stage acid phosphatase activity is absent from these structures. However, high thiamine pyrophosphatase and nucleoside diphosphatase activities remain in the alveolar sacs during the whole life cycle. On the other hand, acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in thick membrane cisternae of theronts. Based on the morphological aspects and enzymatic content the thick membrane cisternae of the cell cortex are designated as golgian-like cisternae. The cytochemical results point out a relationship between the alveolar sacs and the Golgi complex.     

Enzyme Cytochemistry of the Alveolar Sacs and Golgian-Like Cisternae in the Ciliate Ichthyophthirius multifiliis

In the cell cortex of the parasitic ciliate Ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. The thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. Using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs of trosphozoites. In the endoplasmic reticulum acid phosphatase activity was not detected and only very small amounts of thiamine pyrophosphatase and nucleoside diphosphatase reaction product were observed. After exit from the host, a reduction in acid phosphatase activity was evident in the alveolar sacs. At theront stage acid phosphatase activity is absent from these structures. However, high thiamine pyrophosphatase and nucleoside diphosphatase activities remain in the alveolar sacs during the whole life cycle. On the other hand, acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in thick membrane cisternae of theronts. Based on the morphological aspects and enzymatic content the thick membrane cisternae of the cell cortex are designated as golgian-like cisternae. The cytochemical results point out a relationship between the alveolar sacs and the Golgi complex.     

Ultrastructural changes in the liver of the sand lamprey,Lampetra reissneri,during sexual maturation

Ultrastructural changes of hepatocytes were examined in the sand lamprey,Lampetra reissneri, during various phases of the life cycle. In hepatocytes of ammocoetes, the rough endoplasmic reticulum was composed of short cisternae and the Golgi apparatus were scarcely developed, showing no sexual differences at this stage of life cycle. In hepatocytes of female lampreys at the metamorphic stages 4 to 5, the rough endoplasmic reticulum was developed to form long parallel cisternae and the Golgi apparatus were well-developed. The rough endoplasmic reticulum developed further to form stacks of long parallel cisternae extending over the cytoplasm in hepatocytes of females at the young adult stage, and became composed of both long parallel and vesicular cisternae in the cells of females at the adult stage. The Golgi apparatus were invariably welldeveloped in hepatocytes of young adult and adult females. No consipcuous development was observed in profiles of the rough endoplasmic reticulum and the Golgi apparatus in hepatocytes of males during and after metamorphosis. The ultrastructural changes of the rough endoplasmic reticulum and the Golgi apparatus observed in hepatocytes of female sand lampreys are considered to have an intimate relation to the activity of vitellogenin synthesis in the liver, and it is suggested that the hepatocytes begin to rapidly synthesize vitellogenin in the sand lamprey at the metamorphic stages 4 to 5.     

内质网及其标志酶在离体培养脊髓神经元中的发育变化

本文采用形态学与细胞化学相结合的方法,在超微结构水平观察了与突触酶、受体和结构蛋白的合成有关的内质网和高尔基复合体、GERL以及它们的标志酶的发育变化。结果表明神经元本身有一发育过程,发育早期的细胞器较少,成熟时逐渐增多,以内质网和高尔基复合体最为明显。用G一6一Pase、TPPase和CMPase可分别标记内质网及同源结构、高尔基复合体的成熟而膜囊和GERL。这些酶的出现及阳性水平与神经元的发育呈同步关系。可作为判断细胞分化程度和功能状态的指标。G-6-Pase还分布在突触后树突的内质网中,突触形成大都从含G-6-Pase阳性内质网的树突开始。本文对内质网及G-6-Pase在神经元中的发育变化及功能进行了讨论。     

Substructure of cisternal organelles of neuronal perikarya in immature rat brains revealed by quick-freeze and deep-etch techniques

Summary Membrane-bounded organelles possessing cisternae, i.e., rough endoplasmic reticulum and Golgi apparatus, in immature rat central neurons were examined by quick-freeze and deep-etch techniques to see how their intracisternal structures are organized and how ribosomes are associated with the membrane of the endoplasmic reticulum. Cisternae of endoplasmic reticulum, 60–100 nm wide, were bridged with randomly-distributed strands (trabecular strands, 12.5 nm in mean diameter). Luminal surfaces of cisternae of the endoplasmic reticulum were decorated with various-sized globular particles, some as small as intramembrane particles, and others as large as granules formed by soluble proteins seen in the cytoplasm. A closer examination revealed much thinner strands (3.3. nm in mean diameter). Such thin strands were short, usually winding toward the luminal surface, and sometimes touching the luminal surface with one end. Ribosomes appeared to be embedded into the entire thickness of cross-fractured membranes of endoplasmic reticulum, that is, their internal portions appeared to be situated at almost the same level as the cisternal luminal surface. From the internal portion of ribosomes, single thin strands occasionally protruded into the lumen, suggesting that these thin strands were newly synthesized polypeptides. A horizontal separation within ribosomes appeared to occur at the same level as the hydrophobic middle of the membrane of the endoplasmic reticulum. Interiors of the Golgi apparatus cisternae, which were much narrower than cisternae of endoplasmic reticulum, were similarly bridged with trabecular strands, but the Golgi trabecular strands were thinner and more frequent. Their cisternal lumina were also dotted with globular particles. No identifiable profiles corresponding to the thin strands in the endoplasmic reticulum were observed. Golgi cisternae showed a heterogeneous distribution of membrane granularity; the membrane in narrow cisternal space was granule-rich, while that in expanded space was granule-poor, suggesting a functional compartmentalization of the Golgi cisternae.     

Plasticity of the endoplasmic reticulum in three cell types of slugs poisoned by molluscicides

Summary In three cell types of slug tissue-the crypt, mucous and storage cell-ultrastructural alterations of the endoplasmic reticulum (ER) can be induced by oral application of the pesticides Cloethocarb, metaldehyde, or Dimilin. In the crypt cells of the hepatopancreas, the narrow-luminar cisternae of the rough endoplasmic reticulum which are parallelly arranged in controls get slightly dilated, vesiculated and form circular arrays. Intermediate stages between narrow luminar, vesiculated and circularly arranged ER can be observed. In the mucous cells of the skin and the stomach, the wideluminar cisternae of the rough endoplasmic reticulum the lumen of which contains tubular-like structures become heavily dilated. Also in this cell type, intermediate stages between dilated cisternae without tubular-like structures and non-dilated cisternae can be observed. In the storage cells of the crop, in which lipid storage is reduced after molluscicide application, the formation of a special type of ER characterized by locally enlarged ER-cisternae, broken through by several cytoplasmic strings, becomes obvious.     

Annulate lamellae,lamellar bodies and subsurface cisternae in neurons of the avian hyperstriatum accessorium

Summary Structures identified as annulate lamellae, lamellar bodies and subsurface cisternae were found in neurons of the hyperstriatum accessorium of the avian forebrain. Annulate lamellar arrays with up to six lamellae were present in the larger somata. The lamellae were made up of fused smooth-surfaced cisternae forming pores or annuli and were surrounded by a dense filamentous to granular material. Stacks of nonfenestrated, parallel, regularly spaced cisternae, designated as lamellar bodies, also appeared in the cytoplasm. When flattened they were reminiscent of the electron dense subsurface cisternae. Continuity could be demonstrated between peripherally located subsurface cisternae and lamellar bodies. The dense filamentous to finely granular substance was also located between these structures. Annulate lamellae, lamellar bodies and subsurface cisternae were always observed in conjunction with the rough endoplasmic reticulum. The functional significance of these structural associations is considered.     

Submicroscopic study of adenohypophyseal cells with the hypophysis incubated in a hypertonic solution. I. The distribution of acid phosphatase, thiamine pyrophosphatase and arylsulfatase activities

In the rat adenohypophyseal mammotrophs and somatotrophs, activities of acid phosphatase, thiamine pyrophosphatase and aryl sulphatase were defined after the incubation of the pituitary gland in the medium containing 1.65 M sucrose. Following 60--120 minutes of the incubation the above enzymes were found, in addition to their usual sites, in all cisternae of the Golgi apparatus and the rough endoplasmic reticulum as well as within the perinuclear cisternae. The mechanism of the above alterations is discussed, and a suggestion is put forward that the emergence of enzymatic activities in the above structures may reflect their biogenetic pathways in the cell.     

Changes in cell polarity during mitosis in rat parotid acinar cells.

We studied the ultrastructure and cytochemistry of mitotic parotid acinar cells in vivo after induction of mitosis by isoproterenol injection. With entrance of the cells into the division cycle, the Golgi apparatus lost its characteristic stacked structure and internal polarity among the cisternae, appearing as fragments distributed throughout the cytoplasm. These fragments consisted of electron-lucent vesiculotubular structures and electron-dense 70-nm vesicles; neither component showed thiamine pyrophosphatase activity, a marker for trans cisternae of the Golgi apparatus, but the 70-nm vesicles showed a positive reaction for osmium impregnation, indicating retention of the cis nature. The rough endoplasmic reticulum was dilated and fragmented. Recovery of the structure of Golgi apparatus and rearrangement of rough endoplasmic reticulum occurred in daughter cells during telophase. These changes were the same as those observed after drug-induced inhibition of protein transport. The secretory granules were not dispersed but were divided into two groups with which centrioles were closely associated. Both groups migrated with the centrioles as far as the next interphase. The distribution of 5'-nucleotidase on the luminal plasma membrane showed no change during the process of division, thus demonstrating that surface polarity was maintained during mitosis. These changes in organelle structure and distribution may be due to the conversion of cell function from a secretory to a mitotic action.     

Organelle distribution in chick neuroepithelial cells: effects of colchicine and cytochalasin B

The intracellular distribution of mitochondria, cytoplasmic inclusions and rough endoplasmic reticulum cisternae of chick neuroepithelial cells was investigated at neurulation stages 6, 8, 10 and 12. These neuroepithelial cells were subdivided into three zones: apical, median and basal and the distribution percentages of distribution of these organelles were obtained. Mitochondrial distribution was related to the energy supply that mitochondria provide for apical microfilament contraction. Cytoplasmic inclusions were distributed preferentially in the apical zone of the neuroepithelial cells during the four stages. Rough endoplasmic reticulum cisternae were homogeneously distributed in the three zones at stages 10 and 12, but at stages 6 and 8 there are more elevated percentages of rough endoplasmic reticulum in the apical zones than in the other zones. Experimental treatments with colchicine and cytochalasin B does not modify the patterns of mitochondria and rough endoplasmic reticulum cisternae but alters the distribution of cytoplasmic inclusions. Finally, there is a correlation in the normal neurulating neuroepithelial cells between the distributions of mitochondria and rough endoplasmic reticulum distribution and between the distributions of mitochondria and cytoplasmic inclusions distribution. This relationship is retained in the treated neuroepithelial cells.     

Cytochemical localization of terminal N-acetyl-D-galactosamine residues in cellular compartments of intestinal goblet cells: implications for the topology of O-glycosylation

The O-linked oligosaccharides of mucin-type glycoproteins contain N- acetyl-D-galactosamine (GalNAc) that is not found in N-linked glycoproteins. Because Helix pomatia lectin interacts with terminal GalNAc, we used this lectin, bound to particles of colloidal gold, to localize such sugar residues in subcellular compartments of intestinal goblet cells. When thin sections of low temperature Lowicryl K4M embedded duodenum or colon were incubated with Helix pomatia lectin- gold complexes, no labeling could be detected over the cisternal space of the nuclear envelope and the rough endoplasmic reticulum. A uniform labeling was observed over the first and several subsequent cis Golgi cisternae and over the last (duodenal goblet cells) or the two last (colonic goblet cells) trans Golgi cisternae as well as forming and mature mucin droplets. However, essentially no labeling was detected over several cisternae in the central (medial) region of the Golgi apparatus. The results strongly suggest that core O-glycosylation takes place in cis Golgi cisternae but not in the rough endoplasmic reticulum. The heterogenous labeling for GalNAc residues in the Golgi apparatus is taken as evidence that termination of certain O- oligosaccharide chains by GalNAc occurs in trans Golgi cisternae.     

Virus-neuron interactions in the mouse brain infected with Japanese encephalitis virus

The virus-host interactions between Japanese encephalitis (JE) virus and mouse brain neurons were analyzed by electron microscopy. JE virus replicated exclusively in the rough endoplasmic reticulum (RER) of neurons. In the early phase of infection, the perikaryon of infected neurons had relatively normal-looking lamellar RER whose cisternae showed focal dilations containing progeny virions and characteristic endoplasmic reticulum (ER) vesicles. The reticular RER, consisted of rows of ribosomes surrounding irregular-shaped, membrane-unbounded cisternae and resembled that observed in JE-virus-infected PC12 cells, were also seen adjacent to the lamellar RER. The appearance of the reticular RER indicated that RER morphogenesis occurred in infected neurons in association with the viral replication. The fine network of Golgi apparatus was extensively obliterated by fragmentation and dissolution of the Golgi membranes and their replacement by the electron-lucent material. As the infection progressed, the lamellar RER was increasingly replaced by the hypertrophic RER which had diffusely dilated cisternae containing multiple progeny virions and ER vesicles. The Golgi apparatus, at this stage, was seen as coarse, localized Golgi complexes near the hypertrophic RER. In the later phase of infection, RER of infected neurons showed a degenerative change, with the cystically dilated cisternae being filled with ER vesicles and virions. Small, localized Golgi complexes frequently showed vesiculation, vacuolation, and dispersion. The present study, therefore, indicated that during the viral replication the normal lamellar RER which synthesized neuronal secretory and membrane proteins was replaced by the hypertrophic RER which synthesized the viral proteins. The hypertrophic RER eventually degenerated into cystic RER whose cisternae were filled with viral products. The constant degenerative change which occurred in the Golgi apparatus during the viral replication suggested that some of the viral proteins transported from RER to the Golgi apparatus were harmful to the Golgi apparatus and that increasing damage to the Golgi apparatus during the viral replication played the principal role in the pathogenesis of JE-virus-infected neurons in the central nervous system.     

内质网及其标志酶在离体培养脊髓神经元中的发育变化

In an attempt to elucidate the relationship between synapse formation and cell development, the morphology and cytochemistry of the endoplasmic reticulum and its enzymic marker, glucose-6-phosphatase (G-6-Pase), in cultured mouse spinal neurons were investigated ultrastructurally. It was found that in the early period of the development, neurons were characterized by scarceness of organelles; only a few of granular or agranular endoplasmic reticulum and mitochondria were seen. The endoplasmic reticulum and nuclear envelope were packed specifically with G-6-Pase resection product but the product was weak. After a period of culture, most of the neurons had well-developed endoplasmic reticulum, Golgi apparatus, mitochondria and microtubules, etc. The Golgi apparatus was relatively large, having some cisternae associated with vesicles. Either concave of convex face of the saccules was labeled by thiamine pyrophosphatase (TPPase) specifically. GERL, labeled by cytidine monophosphatase (CMPase), was also seen close to the inner or outer face of some Golgi apparatus. The endoplasmic reticulum at this stage was distributed throughout the cytoplasm, including that in dendrites; its enzyme marker (G-6-Pase) localized consistently within the lumen of all endoplasmic reticulum, nuclear space and subsurface cisternae, and frequently in the concave saccules of the Golgi apparatus. After a long-term culture, some neurons became "aged". The endoplasmic reticulum cisternae enlarged and G-6-Pase reaction reduced. Along with the neuronal development, especially maturation of the endoplasmic reticulum and its enzymic marker, synapse formation was begun at the neuropile area. The axo-dendritic synapses always occurred between the axonal terminals and dendrites where the endoplasmic reticulum had showed positive G-6-Pase reactions. Considering the fact, it suggests that the appearance and change of these specific enzymes may be related to the maturation of the neurons in vitro, and also related to the synapse formation between neurons.     

Ultrastructural changes in neurons and neuroglia of the avian telencephalon (Hyperstriatum Accessorium) following tri-ortho-cresyl-phosphate intoxication

Summary Ultrastructural reactions of neurons of the avian forebrain following tri-ortho-cresyl-phosphate (TOCP) poisoning are described. These neurons show a marked increase in the rough endoplasmic reticulum (RER), with RER specializations such as lamellar bodies and subsurface cisternae, as well as a proliferation of the Golgi complex and neurofilaments. In addition, an increase in the number of dense bodies and mitochondrial osmiophilia is noted. Similar changes can also be observed in the neuroglia. These alterations appear 10–13 days after TOCP ingestion.     

Ultrastructural investigation of ACTH immunoreactivity in arcuate and supraoptic nuclei of the rat

Summary Fine structural localization of an ACTH-like substance was obtained in neurons of the rat arcuate nucleus using immuno-electron microscopy, whereas it could not be confirmed that ACTH-containing cell bodies are present in the supraoptic nucleus. The immunoreactive cells of the arcuate nucleus appeared to be more numerous than the unreactive neurons. Immunostaining was carried out before embedding in resin. Empty vesicles of irregular shape were found in dendrites of immunoreactive arcuate neurons, but their significance and nature remain enigmatic. The reaction product was distributed uniformly throughout the cytoplasm of the ACTH-positive cells, except that the mitochondria, rough endoplasmic reticulum and Golgi vesicles and cisternae were devoid of PAP molecules. This distribution differed from the localization reported in ACTH-secreting cells of the rat anterior pituitary, where the reaction product was found in the rough endoplasmic reticulum and Golgi complex as well as in secretory granules.     

Fine-structural localization of proenkephalin mRNAs in the hypothalamic magnocellular dorsal nucleus of the guinea pig: a comparison of radioisotopic and enzymatic in situ hybridization methods at the light- and electron-microscopic levels

With the aim of localizing proenkephalin mRNAs in neurons of the hypothalamic magnocellular dorsal nucleus of the guinea pig, we compared the in situ hybridization signals obtained on Vibratome sections with a method employing either a biotinylated or a digoxigenin-labeled oligonucleotide detected by means of the alkaline phosphatase reaction. Since the hybridization approach using the biotinylated probe was more sensitive than the digoxigenin method, the ultrastructural localization of hybrids in neurons of the magnocellular dorsal nucleus was studied by the use of the former procedure, and was further compared with results of in situ hybridization using a ³⁵S-labeled probe. Biotin was detected via an amplified avidin-biotin-peroxidase complex. Radioactive hybrids were localized over extended cytoplasmic compartments rich in rough endopoasmic reticulum and also in nuclear indentations. The method based on biotinylated probe proved to be sensitive and provided high-resolution labeling in well-preserved specimens. Proenkephalin mRNAs were clearly localized within circumscribed cytoplasmic compartments. The immunoprecipitates were mainly observed within the rough endoplasmic reticulum, especially at the periphery of the cell. The reticulum was dominated by elongated parallel cisternae. The labeling also appeared in a paranuclear position, mainly in nuclear indentations. The labeling was found on the outer surface of the endoplasmic lamellae. The remainder of the reticulum was unlabeled. Neuronal processes were free of labeling.     

Cytochemical localization of thiamine pyrophosphatase and nicotinamide adenine dinucleotide phosphatase activities in rat epiphyseal chondrocytes

Two phosphatase activities, which have been reported to be associated with the Golgi apparatus in several cellular types, have been cytochemically demonstrated in rat epiphyseal cartilage. This was the case for thiamine pyrophosphatase (TPPase) which was detected in Golgi trans face cisternae and also in nascent or immature secretory granules of chondrocytes. beta-Nicotinamide adenine dinucleotide phosphatase (beta-NADPase), on the other hand, was localized mainly in the endoplasmic reticulum region of both proliferative and hypertrophic chondrocytes. Most of the beta-NADPase reaction was shown to be associated with the cytoplasmic side of the rough endoplasmic reticulum membranes and also partially dispersed throughout the cytosol background. We suggest that beta NADPase in chondrocytes could be an enzyme with different properties from that described in other secretory cells.     

Endogeneous peroxidase activity in the frog thyroid gland

Summary The fine structural localization of the endogeneous peroxidase activity in the thyroid of the young frog was studied. The reaction product for peroxidase was observed over the peripheral luminal colloid and apical region of the follicular epithelial cell. Most apical small granules and some parts of Golgi lamellae and a few Golgi vesicles were specifically stained. The cisternae of rough endoplasmic reticulum and the nuclear cisternae did not demonstrate any positive reaction for peroxidase activity with difference from that of various cells of mammalia. In this study, only mature peroxidase seems to be positive for its reaction and the enzyme in the rough endoplasmic reticulum is considered to be too immature to react for DAB method in the frog thyroid cell. The relationship between the localization of peroxidase reaction and the site of the iodination of thyroglobulin was discussed.     

Paired cisternae of endoplasmic reticulum in developing ovarian oocytes of the golden hamster

Paired cisternae of rough endoplasmic reticulum linked together by two parallel structures exhibiting periodic striations have been observed in the cytoplasm of small pre-antrum oocytes in the golden hamster. They are present only in oocytes from animals older than 3 weeks of age. Two or more such pairs may be associated with one another, and similar structures have been observed in contact with the nuclear envelope. The peak incidence of the paired membranes coincides with a sharp increase in rough endoplasmic reticulum as the oocyte commences rapid growth. A suggested role for the paired membranes in production of new endoplasmic reticulum is discussed.