Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat gastric mucosal cells were isolated with the aid of 0.1% collagenase and Dispase. Pepsinogen secretion from these cells was stimulated by carbachol, cholecystokinin octapeptide (CCK(S)-8) and pentagastrin, but not by histamine. Attempts to obtain a sufficient number of cells using a higher concentration of Dispase resulted in disappearance of the responses to secretagogues. However, when gastric mucosal cells thus prepared were cultured for 24 h in a CO2 incubator, they were found to respond not only to carbachol, CCK(S)-8 and pentagastrin, but also to histamine, resulting in an increase in pepsinogen secretion. The secretagogue-induced pepsinogen secretion was inhibited by its antagonist in a dose-dependent manner. These results suggest that the receptor present in chief cells for pepsinogen secretion was destroyed during the isolation procedure and regenerated during culture.
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PMID:Pepsinogen secretion from cultured rat gastric mucosal cells. 259 21

The cellular distribution of histamine N-methyltransferase was studied in rabbit gastric mucosa. The fundic mucosa was dispersed by collagenase treatment in Hanks' or calcium-free medium. In calcium-free medium, the number of dispersed cells/g wet tissue, as well as their viability was increased; histamine N-methyltransferase recovery was up to three-fold larger than in cells prepared in Hanks' medium. Furthermore, the calcium-free medium led to a greater acid secretory response, whereas the cellular pepsinogen content tended to be lower. Histamine N-methyltransferase activity was found in all cell fractions but was higher in the larger cell types. The enzyme activity showed only a partial correlation with either oxyntic or chief cells. These results indicate that the use of calcium-free medium to disperse and isolate rabbit mucosal cells improves cell quality. Histamine N-methyltransferase in the rabbit fundic mucosa, is found in more than one cell type, primarily the oxyntic and chief cells.
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PMID:Histamine methyltransferase in dispersed cells from rabbit fundic mucosa. 278 23

Specific binding sites for cholecystokinin (CCK) have been identified and characterized in fundic glands isolated by collagenase treatment from guinea pig gastric mucosa using a biologically active 125I-labeled derivative of the C-terminal octapeptide of CCK (125IIE-CCK-8). The time course of binding to these glands was rapid, temperature dependent and saturable. At 24, 30 and 37 degrees C, half-maximal binding was reached at 5 min and full binding at 30 min. The addition of a large excess of CCK-8 after 15 and 30 min of binding at 24 degrees C caused a prompt and rapid decline in radioligand bound showing that the interaction was reversible. There was a progressive decline in the amount of 125IIE-CCK-8 bound to fundic glands with increasing concentrations of CCK-8 and other structurally related peptides. Gastrin II displaced 50% of the radioligand at 1.6nM, CCK-8 at 3.2nM, gastrin I at 16nM, and desulfated-CCK-8 and pentagastrin at 59nM. Secretin did not displace the radioligand from fundic glands at 1.0uM. The binding was also tissue specific as glands isolated from the antral mucosa did not contain specific binding sites for 125IIE-CCK-8. This data provides evidence for specific receptors for CCK on gastric fundic glands that may be involved in the control of acid and pepsinogen secretion.
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PMID:Identification and characterization of a specific receptor for cholecystokinin on isolated fundic glands from guinea pig gastric mucosa using a biologically active 125I-CCK-8 probe. 632 10

Our aim was to develop a fibroblast-free monolayer culture of human gastric mucosal cells, using the specimens obtained by routine endoscopic biopsy. Human gastric mucosa obtained from normal volunteers by endoscopic biopsy was dissociated from collagenase and hyaluronidase. Dissociated cells were cultured in supplemented Coon's modified Ham's F-12 medium. Within 24 hr of inoculation, the cells were attached to the culture dishes. This was followed by cellular outgrowth. On phase-contrast microscopy, all cells had epithelial characteristics and fibroblasts were not observed. Ninety percent of cells contained periodic acid Schiff reaction-positive mucous granules after diastase digestion consistent with mucous epithelial cells. Two percent of the cells gave a strong reaction for succinic dehydrogenase activity (parietal cells). Immunohistochemical staining for pepsinogen in cultured cells was negative. On EM, microvilli-like projections, junctional complexes, Golgi apparatus, and mucous granules were apparent in the majority of cells. Mitotic figures were observed by day 3 with Giemsa staining. Autoradiographically, these cells were able to incorporate [3H]TdR into the nuclei. Cells were capable of synthesizing DNA, and this function was inhibited by cycloheximide. Cells could be cultured for up to two weeks without fibroblast contamination. A method of primary monolayer culture of human gastric mucosa obtained by a routine endoscopic biopsy has been successfully developed.
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PMID:A monolayer culture of human gastric epithelial cells. 686 89

The effects of aspirin and ibuprofen on pepsinogen secretion were studied in isolated human peptic cells prepared from endoscopically obtained biopsy specimens after collagenase digestion, mechanical disruption, and percoll gradient centrifugation. Pharmacological concentrations of aspirin and ibuprofen (10(-8)-10(-4) M), potentiated histamine (10(-6)-10(-4)M) and forskolin (10(-5)M) stimulated pepsinogen secretion without affecting basal secretion, acetylcholine (10(-6)M) stimulated pepsinogen secretion or cell vitality. Augmentation of secretagogue stimulated pepsinogen secretion was dependent on extracellular calcium because potentiation was abolished by calcium depletion of the medium. Cimetidine inhibited the potentiation effect on histamine but not on forskolin stimulated pepsinogen secretion, thus suggesting that this augmentation was independent of histamine H2 receptors. Of interest, potentiation was also independent of endogenous prostaglandin inhibition because exogenous addition of prostaglandin E2 and D2 increased both basal and acetylcholine stimulated pepsinogen secretion in a dose dependent way, but they did not modify histamine or histamine plus aspirin or ibuprofen stimulated pepsinogen secretion. In conclusion, aspirin and ibuprofen potentiate secretagogue stimulated pepsinogen secretion by dispersed human peptic cells and this might be an additional mechanism of non-steroidal anti-inflammatory drug (NSAID) induced gastric injury. This potentiation effect is regulated by calcium, independent of endogenous prostaglandin inhibition and seems to act on pepsinogen secretion at a post-receptor site.
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PMID:Non-steroidal anti-inflammatory drugs and prostaglandin effects on pepsinogen secretion by dispersed human peptic cells. 779 13

For the purpose of studying pepsinogen secretion from gastric chief cells, we established a monolayer culture system of guinea pig chief cells and an enzyme immunoassay (EIA) system specific for guinea pig pepsinogen. Dispersed chief cells were obtained from gastric mucosa of a guinea pig using collagenase, GEDTA, and Percoll solution, suspended in DMEM/F-12 (1/1 containing 10% FCS) media, and cultured for 70hr. Then the monolayer culture system was established. Pepsinogen was purified from gastric mucosa of a guinea pig using DEAE-Sephacel and Sephacryl S-200 columns. Antibody to pepsinogen was raised by immunizing rabbit with the purified pepsinogen. A two-site EIA system was then established using beta-galactosidase-labeled Fab' antibody. The EIA system showed sensitivity to measure above 1.5ng of guinea pig pepsinogen, and the monolayer culture system responded well to secretagogues. These systems are useful for studying pepsinogen secretion.
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PMID:[The establishment of a monolayer culture system of guinea pig chief cells and an enzyme immunoassay system for guinea pig pepsinogen]. 846 66

Cell suspensions from the guinea pig gastric mucosa were obtained using a pronase/collagenase isolation method, and cultured on Petri dishes in minimum essential medium at 37 degrees C. For proper identification of different gastric cell types in cytospots, cell suspensions or culture, selective staining methods were employed, modified and evaluated. Mucous cells and mucous neck cells were detected by use of lectins. Mucous cells were stained on cytospots and in primary cultures with lectins from peanut, Helix pomatia, Ulex europaeus, wheat germ, and from soybean. Vital chief cells in suspensions but not in culture, were selectively stained by Nile blue sulphate, brilliant cresyl blue or the fluorescence dye dihexyloxacarbocyanine iodide. Pepsinogen granules of isolated and cultured chief cells were detected with a polyclonal antibody against porcine pepsinogen. Isolated parietal cells were identified in cytospots by using acidophilic dyes (aurantia, eosin). In suspensions and in cultures vital parietal cells were identified by enzymatic detection of succinic dehydrogenase or carboanhydrase activity and by the vital stain Janus green. In cultures exclusively, parietal cells were additionally identified by the vital stain rhodamine. Cytochemically, they were identified with phalloidin by binding to actin filaments. Endocrine cells in the suspension were visualised immunocytochemically with antibodies directed against different amines or peptides. Fibroblasts and endothelial cells were identified after isolation and in primary culture with a vimentin antibody. Mast cells in suspension were either visualised by a histamine antibody or by metachromatic staining behaviour to toluidine blue, respectively. Endothelial cells in suspension or culture were distinguished from fibroblasts by endocytosis of acetylated low-density-lipoprotein. In conclusion, the developed methods are highly suitable to identify guinea pig gastric cells after isolation and follow up their fate in primary culture.
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PMID:Suitability of different staining methods for the identification of isolated and cultured cells from guinea pig (Cavia aperea porcellus) stomach. 883 36

The effects of indomethacin on pepsinogen secretion were studied in isolated human peptic cells prepared from endoscopically obtained biopsies after collagenase digestion, mechanical disruption and percoll gradient centrifugation. Low concentrations of indomethacin (10(-8)-10(-10) M) stimulated basal pepsinogen secretion. Higher doses of indomethacin (10(-5)-10(-6) M) potentiated histamine (10(-4) M) and db-cAMP (10(-4) M)-stimulated pepsinogen secretion without affecting acetylcholine (10(-6) M) and CCK-8-stimulated pepsinogen secretion or cell vitality. Increase of pepsinogen secretion was dependent on extracellular calcium because potentiation was abolished by calcium depletion of the medium. We conclude that indomethacin potentiates basal and secretagogue-stimulated pepsinogen secretion by dispersed human peptic cells and this might be an additional mechanism of NSAID-induced gastric injury. This potentiation effect is regulated by calcium and independent of endogenous prostaglandin inhibition.
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PMID:[Effect of indomethacin on the secretion of pepsinogen in isolated human cells in vitro]. 900 95

The purpose of this study was to characterize time-dependent changes in pepsinogen (PG) synthesis of porcine gastric chief cells during long-term monolayer culture. Porcine chief cells were isolated by pronase/collagenase treatment of fundic mucosa and enriched by density gradient and counterflow centrifugation. PG isoenzymes were identified in [L-35S]methionine-labelled cultured chief cells by native polyacrylamide gel electrophoresis followed by phosphor imager analysis, protease detection and immunoblots with specific PG A and C antibodies. The obtained results suggest that porcine chief cell cultures, after an initial settling period, reached an approximate steady state in total protein content and synthesis as well as in PG content and isoenzyme pattern from days 3 to 9 of culture. The latter was characterized by the presence of at least two PG A and two PG C isoenzymes. During the supposed steady-state total PG synthesis averaged out at 34 +/- 2% of total protein synthesis, as detected by [L-35S]methionine incorporation, due to the synthesis of, mainly, PG A2 and, to a much lesser extent, PG C and A1. In line with an active secretion, PG A2 proportion was on average significantly higher in released (44 +/- 3%) than in intracellular labelled proteins (19 +/- 2%). In addition, PG release from chief cells cultured for 6 and 9 days could be stimulated by cholecystokinin-octapeptide. These data suggest that porcine chief cells in monolayer culture are a model well suited for the quantitative and qualitative characterization of PG isoenzyme synthesis and release during long-term investigations, for which an establishment of a culture steady state appears to be a useful prerequisite.
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PMID:Pepsinogen synthesis during long-term culture of porcine chief cells. 939 83