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:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The role of collagen in ultrafiltration properties of the glomerular basement membrane (GBM) was tested after a single administration of bacterial collagenase, using native ferritin as a tracer which does not pass through the GBM under physiological conditions. Experiments were performed both in situ and with isolated kidneys. Increased permeability to ferritin occurs 6 hr following enzyme perfusion and becomes patent after 30 hr, numerous tracer molecules appearing in urinary space, without any readily observable changes either in distribution of fixed negative charges (as revealed by colloidal iron and polyethyleneimine) or in structural organization of the glomerulus. Selective permeability of the GBM is progressively restored so that ferritin is almost confined to capillary lumen one month after enzyme injection. We conclude that collagen plays an important part in restricting plasma protein filtration.
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PMID:Enhancement of glomerular permeability to anionic ferritin induced by kidney perfusion with collagenase. 298 77

To investigate which cells of the liver express the receptor for transferrin, isolated rat liver cells produced by collagenase perfusion were fractionated by repeated differential centrifugation to produce hepatocytes (95% + 1%, mean +/- SD, n = 4) and nonparenchymal cells (97% + 1%, n = 3). Saturable, high-affinity binding of 125I-transferrin was demonstrated on intact cells at 4 degrees C, with average receptor numbers 20,900 +/- 3,160 (mean + SD, n = 4) for hepatocytes and 5,500 + 1,520 (n = 3) for nonparenchymal cells. Total cellular receptors measured in detergent permeabilized hepatocytes were 42,000 +/- 18,330 (mean +/- SD, n = 3) per cell and 14,760 +/- 7,120 (n = 3) per cell in the nonparenchymal fraction. Immunocytochemical demonstration of transferrin using antitransferrin, peroxidase antiperoxidase complex confirmed that both cell types bound transferrin. There was heterogeneity of the staining reaction since there was no detectable staining on 40% of hepatocytes and 60% of nonparenchymal cells. Microdensitometric analysis of the staining product corroborated the biochemical evidence that hepatocytes have, on average, more than three times more transferrin receptors than do nonparenchymal cells. These findings support the concept that the hepatocyte has a central role in the uptake and storage of transferrin iron.
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PMID:Heterogeneous distribution of transferrin receptors on parenchymal and nonparenchymal liver cells: biochemical and morphological evidence. 353 27

Noninbred Sprague-Dawley rats were maintained on a choline-deficient diet containing 0.05% ethionine. After 10-13 weeks, livers were dispersed with collagenase, lysozyme, collagenase and hyaluronidase. Pronase, or a selected batch of trypsin. The highest yield of cells with histochemically demonstrable gamma-glutamyl transpeptidase (GGT) was obtained with trypsin. After velocity sedimentation in an isokinetic gradient of Ficoll in tissue culture medium, two modal populations of cells with histochemically demonstrable GGT were observed. The first mode contained cells that were morphologically different from hepatocytes and that may be oval cells. The second, more rapidly sedimenting modal population of cells with GGT was morphologically similar to hepatocytes as assessed with Wright's stain; the location of this population in the gradient was the same as the location of cells with the appearance of hepatocytes that lacked iron and that had decreased glucose 6-phosphatase. In multiple experiments, the purest fractions contained 71.7 +/- 3.5% cells (mean +/- SD) with the appearance of hepatocytes with histochemically demonstrable GGT.
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PMID:Separation of two populations of cells with gamma-glutamyl transpeptidase from carcinogen-treated rat liver. 611 83

Daily administration of ferric nitrilotriacetate (5 ml/Kg b.w./day i.p.) induces in a few weeks liver siderosis; continuous treatment of the same animals with the carcinogen 2-Acetaminofluorene (300 mg/Kg of diet) results in the appearance of several iron devoid hyperplastic areas or nodules, where enzyme histochemistry reveals gamma-GT activity as well as G-6-Pase disappearance. The perfusion of the liver with calcium-free Hanks solution plus collagenase allows an easy isolation of the hepatocytes, whereas a partial separation of the different kinds of cells can be achieved by isopycnic gradient sedimentation.
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PMID:[Induction, characterization and isolation of preneoplastic hepatocytes following combined treatment with 2-acetaminofluorene and ferric nitrilotriacetate]. 611 69

Iron overload is known to affect the liver. In order to study the effect of iron on various liver cellular and subcellular compartments and the alterations due to mobilization of iron, an experimental model has been developed previously. In this study iron stores in parenchymal and non-parenchymal cells have been investigated during iron loading and unloading. Following completion of the experimental procedures, liver cells were isolated by means of collagenase perfusion (parenchymal cells) and pronase treatment (nonparenchymal cells). It was found that iron overload did not result in significantly increased levels of three lysosomal enzymes, and that the enzyme activities were not altered as iron was mobilized. Iron stores were localized largely in parenchymal cells, and these stores decreased after cessation of iron loading. The iron content was further lowered if the animals were bled. The non-parenchymal cells of the liver initially stored a relatively small part of the administered iron but this increased in the two months following iron loading. On the other hand if the animals were bled there was a pronounced decrease in iron content of these cells as well as in parenchymal cells. It is concluded that iron overload does not affect lysosomal enzymes and that iron stores in both parenchymal and non-parenchymal cells can be mobilized in response to increased demand.
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PMID:Studies on the rat liver following iron overload: an analysis of iron and lysosomal enzymes in isolated parenchymal and non-parenchymal cells. 613 22

Extracellular matrix material (ECM) present during mouse lens morphogenesis was studied histologically by the periodic acid-Schiff, Alcian blue 8GX, pH 2.5, high iron diamine, and Van Gieson methods, and enzymatically with bovine testicular hyaluronidase, Streptomyces hyaluronidase, malt diastase, and collagenase. The basal lamina of the optic vesicle prior to lens placode formation was found to be higher in glycosaminoglycan (GAG) content than was the ectodermal basal lamina. Upon apposition of the optic vesicle and presumptive lens ectoderm, the ECM plus basal laminae appeared as the equivalent of adding both optic vesicle-associated and ectodermal-associated basal lamina. The proposal is made that the initial triggering mechanism of lens morphogenesis consists of a cross-linking and polymerization of optic vesicle-associated GAG to ectodermal-associated glycoproteins resulting in a firm attachment between the structures. Basal lamina associated with the presumptive pigmented retina and also the more ventral part of the interface matrix were found to change from predominantly GAG in early stages to collagen deposits in more advanced stages, temporally coinciding with the appearance of differentiative markers in each structure. This pattern of GAG turnover and replacement by collagen during the course of development is also seen in mouse salivary gland morphogenesis (M. R. Bernfield, S. D. Banerjee, and R. H. Cohn (1972). J. Cell Biol. 52, 674-686.).
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PMID:Histochemical analysis of extracellular matrix material in embryonic mouse lens morphogenesis. 619 23

Seventeen patients with early rheumatoid synovitis underwent synovial biopsy to assess the interrelationship between both ferritin (the intracellular iron storage protein) and Perls' positive iron (ferric iron in loose combination with protein), on the activity and course of rheumatoid disease. The amount of ferritin was associated to a significant degree with the activity of the disease at the time of biopsy, but showed no relation to the way the disease progressed over the following year. In contrast, the amount of Perls' iron bore no relation to the activity of the disease at biopsy, but its presence was associated with persistent disease. It is argued that this association is direct, that ferritin production may fail in a population of synovial macrophages, and that Perls' ferric iron may either be reduced to the ferrous form and promote the formation of toxic free radical species, or stimulate collagenase and prostaglandin release from synovial macrophages.
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PMID:The effect of synovial iron on the progression of rheumatoid disease. A histologic assessment of patients with early rheumatoid synovitis. 620 3

Ionic iron, as the chelate FeNTA, was taken up by rabbit synovial fibroblasts in monolayer culture. Uptake was accompanied by increased production of latent collagenase and PGE2. Concomitant addition of desferrioxamine, a specific chelator of Fe+++, prevented iron uptake and induction of collagenase and PGE2. Collagenase induced by iron may have a role in the pathogenesis of certain disease states associated with abnormal iron deposition.
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PMID:Iron increases collagenase production by rabbit synovial fibroblasts. 625 9

Recently, several authors have emphasized the role of negative sites located in th laminae rarae of the glomerular basement membrane (GBM), in restricting glomerular permeability to anionic macromolecules. In this work, we point out that ultrafiltration properties involve integrity of the GBM. Indeed after intravenous perfusion of bacterian collagenase, anionic ferritin permeates the GBM though negative site distribution (as shown by fixation of colloidal iron) is unaffected.
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PMID:[Effect of collagenase on the permeability of the glomerular basement membrane in the rat kidney]. 626 16

Hepatocytes from livers of rats loaded by Fe-dextran treatment were isolated by an in situ collagenase perfusion technique and evaluated for their biochemical, cytochemical, and morphological characteristics in cell culture. Iron loads 15 times higher than in normal rat liver cells isolated in the same way were retained in the preparations with 40% present as hemosiderin. A simple centrifugation-mathematical approach is described for the calculation of Fe content in the hepatocyte (95%) and reticuloendothelial (5%) fractions in the isolates. The cells were cultured for 22 h without loss of protein synthesis capability or significant changes in cell count, viability, endogenous glutamate-oxaloacetate transaminase (GOT) or Fe and were morphologically similar in most respects to unloaded (normal) hepatocytes similarly cultured. Studies are in progress to assess the utility of these preparations as a model for Fe mobilization from Fe-loaded animals.
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PMID:Characterization of isolated Fe-loaded rat hepatocytes prepared by collagenase perfusion. 629 20


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