Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.3.9 (glucose-6-phosphatase)
3,081 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study has investigated the effect of prenatal alcohol exposure on the qualitative and quantitative ultrastructure of proliferating and differentiated astrocytes in primary cultures as well as on the cytochemical activity of several subcellular phosphatase markers, including acid phosphatase, uridine diphosphatase, thiamine pyrophosphatase, 5'-nucleotidase and glucose-6-phosphatase. The astrocytes were obtained from 21-day-fetuses of both control and alcohol-fed rats. Our results show that several cell components, such as mitochondria, rough endoplasmic reticulum and lysosomes, exhibit qualitative and/or quantitative ultrastructural changes during the process of astrocyte maturation. In some cases these morphological changes are accompanied by variations in the cytochemical activity of enzymes located in these and other cell components, suggesting that these enzymes, and therefore the functional state of these organelles, are modulated during astrocyte development. When prenatally exposed to ethanol, both proliferating and differentiated astrocytes showed striking ultrastructural alterations compared with controls, including an increment of lysosomes as well as a decrease in the values of stereological parameters relative to mitochondria, rough endoplasmic reticulum and Golgi apparatus. Cytochemical analysis of these cells indicates that prenatal exposure to ethanol decreased the activities of all the enzymes tested, except for acid phosphatase, which was increased in both groups of treated astrocytes. These results suggest that prenatal exposure to ethanol could affect astrocytes during development in two different but probably complementary ways: a) by causing a delay in astrocyte maturation and, b) by inducing a direct toxic effect on these cells.
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PMID:Cytochemical and stereological analysis of rat cortical astrocytes during development in primary culture. Effect of prenatal exposure to ethanol. 132 14

Electron microscopic enzyme cytochemical reactions of Entamoeba histolytica trophozoite showed that acid phosphatase (ACP) and cytidine monophosphatase (CMPase) were located in the lysosomes. The lysosome containing enzymes were distributed in the endoplasm and beneath the plasmalemma, and the releasing enzymes by lysosomes excreted outside of the plasmalemma and caused the injury to host cells. The cytochemical positive reactions of catalase and glucose-6-phosphatase (G-6-Pase) showed that E. histolytica contains microbodies and endoplasmic reticulum. The reactive products of peroxidase (POase) were seen in the lysosome-like structure. The reactions of cytochrome oxidase (COase) and succinate dehydrogenase (SDH) were both negative, indicating that E. histolytica lacked mitochondria. The reactions of thiamine pyrophosphatase (TPPase) and nicotinamide adenine dinucleotide phosphatase (NADPase) were both negative, indicating that E. histolytica lacked Golgi body. The reactions of Na(+)-K(+)-ATPase were located on plasmalemma.
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PMID:[Electron microscopic enzyme cytochemistry of Entamoeba histolytica trophozoite]. 133 24

The effects of Ca2+ on the microsomal glucose-6-phosphatase activity were investigated. Evidence is provided that increases by Ca2+ in both the pyrophosphatase and the glucose-6-phosphate-hydrolysing activities are due to an increase in microsomal transport capacity of T2, the phosphate/pyrophosphate-transport protein.
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PMID:Calcium activates glucose-6-phosphatase in intact rat hepatic microsomes. 217 54

Thiamine pyrophosphatase (TPPase), nucleoside diphosphatase (NDPase), and glucose-6-phosphatase (G-6-Pase) were localized by the cerium technique in guinea pig pinealocytes and compared with the corresponding lead technique. NDPase and TPPase were also compared at different pH values using the cerium technique. Vibratome sections of perfusion-fixed tissue were incubated with cerium chloride or lead nitrate. Substrates used were thiamine pyrophosphate (for TPPase), sodium inosine diphosphate (NDPase), and disodium glucose-6-phosphate (G-6-Pase). The 1-2 trans saccules of the Golgi apparatus showed TPPase and NDPase activity but none for G-6-Pase. The endoplasmic reticulum (ER) cisternae and perinuclear space had NDPase and G-6-Pase activity but not TPPase. The abluminal plasmalemma of endothelial cells and the plasmalemma of Schwann cells demonstrated TPPase and NDPase activity but the luminal plasmalemma of the endothelial cells and the plasmalemma of pinealocyte processes showed only NDPase activity. TPPase was active at all pH values tested, but NDPase was most active at pH values of 6.5 and 7.0. Lead phosphate precipitate was frequently seen in nuclei, perinuclear space, ER cisternae, and "synaptic" vesicles when lead was used as the capturing agent. These sites were usually not labeled when cerium was used.
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PMID:Ultrastructural localization of phosphatase activity in the guinea pig pineal gland by the cerium technique. 215 98

In the female urethra, the activity and distribution of 15 enzymes was determined by using both conventional and special histochemical methods. The enzymatic equipment differed according to the type of epithelial lining whose variation is characteristic for the female urethra. In the stratified squamous epithelium of the urethra, alkaline phosphatase, beta-glucuronidase, acetyl-beta-D-glucosaminidase, thiamine pyrophosphatase, and glucose-6-phosphatase exhibited but minimal or no activity, yet the other 10 enzymes studied displayed activity particularly in basally situated cells. Nearer to the lumen of the urethra, the activity in the epithelium kept decreasing and was mostly absent in superficial and desquamated cells. In the pseudostratified columnar and in the transitional epithelium of the urethra, the majority of enzymes showed an evenly distributed activity at all epithelial levels. In the apical parts of the most superficially situated cells bounding the lumen of the urethra, a distinct narrow zone of higher activity was observed. It was seen not only on determining the majority of dehydrogenases but also on examining acid phosphatase and naphthyl esterase. The endocrine cells occurring in the uroepithelial lining of the female urethra displayed, yet always with the exception of squamous epithelium (Zaviacic et al. 1983), distinct activity of acid hydrolytic enzymes, and of the enzymes studied it was particularly acid phosphatase. The majority of the demonstrated enzymes, of the dehydrogenases priority, is to be given to succinate dehydrogenase, enabled to differentiate readily between the highly active striated muscle fibers located in the most peripheral parts of the excisions along the urethral circumference and the smooth musculature of the urethral wall with a lower or only minimal activity.
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PMID:The adult human female urethra. Enzyme-histochemical study. 242 Jan 38

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.
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PMID:[Development of endoplasmic reticulum and its enzymic marker in cultured mouse spinal neurons]. 255 16

Our object was to characterize the morphological changes of coated vesicles and synaptic membranes during synaptogenesis. Neurons from spinal cords of fetal mice were established as isolated cells in primary culture. After a few days in vitro, the neurons extended their neurites and started their interaction. At timed intervals thereafter, cultures were fixed for electron microscopic observation. Coated vesicles were prominent in the neuronal cytoplasm at the time of synaptogenesis (about 7-10 days in vitro). Similar vesicles were seen in continuity with some cisternae in the Golgi regions and there was an increase in number during the synaptogenic period. Indeed it is not established whether the coated vesicles were exocytotic or pinocytotic in nature, but the cisternae which were in continuity with coated vesicles could be labelled by glucose-6-phosphatase (G6Pase) but not by thiamine pyrophosphatase (TPPase). Such vesicles were also seen in continuity with the neuronal plasmalemma near the closest contact site and contributed their undercoating to pre- and postsynaptic densities. The formation of bilateral membrane specialization was described as being structurally similar to synaptic active zones and appeared to be the first definitive sign of synapseformation. It has been suggested that the synaptic dense material may derive wholly or in part from the exocytic coated vesicles which apparently budding off from endoplasmic reticulum cisternae. This incorporation could provide the mechanism for confining specific characteristics of neuronal membrane to the synaptic region.
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PMID:[Morphological study on the role of coated vesicle in the specialization of synaptic membrane in synaptogenesis]. 258 12

New light microscopic visualization methods were developed for the histochemical detection of non-specific alkaline and acid phosphatase, Mg-, Ca- and Na, K-dependent adenosine triphosphatase, myosin adenosine triphosphatase, glucose-6-phosphatase, 5'-nucleotidase and thiamine pyrophosphatase with cerium ions as trapping agents in cryostat and plastic sections. The techniques are based on the conversion of cerium phosphate into cerium perhydroxide by H2O2 which decomposes at 55 degrees-60 degrees C into cerium hydroxide and oxygen radicals. These radicals are able to oxidize diaminobenzidine (DAB) to DAB brown. Addition of nickel ions to the DAB-H2O2 mixture generates bluish-black stained nickel-DAB complexes. Compared with the classical metal precipitation, azo, azoindoxyl and tetrazolium procedures the H2O2-DAB and especially the H2O2-DAB-nickel methods provided identical or superior results in catalytic phosphatase histochemistry and immunohistochemistry when using non-specific alkaline phosphatase as the enzyme label.
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PMID:The cerium perhydroxide-diaminobenzidine (Ce-H2O2-DAB) procedure. New methods for light microscopic phosphatase histochemistry and immunohistochemistry. 285 63

The activities of acid phosphatase, alkaline phosphatase, glucose-6-phosphatase, uridine diphosphatase, inosine diphosphatase, thiamine pyrophosphatase and 5'-nucleotidase have been investigated cytochemically in hepatocytes of the offspring of alcohol-fed rats, using cerium ions as a capturing agent and qualitative and quantitative electron microscopy. All these enzyme activities were decreased in the experimental animals compared with controls not exposed to ethanol. The pattern of deposition of the product of glucose-6-phosphatase activity in the cisternae of the endoplasmic reticulum was also different in the two groups. The phosphatases analyzed are functional markers of different cell components, and the results suggest that prenatal exposure of rats to ethanol causes functional alterations in the endoplasmic reticulum, Golgi apparatus, lysosomes and plasma membrane of hepatocytes.
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PMID:Alterations in the cytochemical activity of several phosphatases in hepatocytes from rats exposed prenatally to ethanol. 286 48

Ultracytochemical reactions for the demonstration of acid phosphatase, glucose-6-phosphatase and thiamine pyrophosphatase, as well as zinc iodide-osmium tetroxide impregnation, revealed the existence of GERL (Golgi apparatus-Endoplasmic Reticulum-Lysosomes) in pinealocytes of the Mongolian gerbil (Meriones unguiculatus). The spatial arrangement of this structure was studied on thick sections using a goniometric stage. Although it was not possible to determine whether GERL in pinealocytes belongs to the Golgi apparatus or to endoplasmic reticulum, it can be concluded that its presence in studied cells signifies that they are considerably more active synthetically than has been believed to date.
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PMID:Ultracytochemical evidence for the presence of GERL in pinealocytes of the Mongolian gerbil (Meriones unguiculatus). 302 41


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