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)

Collagenase from Clostridium histolyticum induced haemorrhages when applied to the surface of dog lung; it exerted a similar effect on mouse lung when injected intrathoracically. Injected into rat paws, bacterial collagenase induced haemorrhage and oedema. Effects of collagenase were prevented by several procedures that inhibit collagenolytic activity (heating at various temperatures and incubation with metal-complexing agents such as EDTA, penicillamine and dithiothreitol). Protein protease inhibitors, dexamethasone and standard acidic anti-inflammatory drugs had only a slight or no effect on collagenase-induced haemorrhages; dexamethasone and acidic anti-inflammatory drugs blocked collagenase-induced oedema. Inhibition of endogenous kinin-releasing mechanisms by administration of hexadimethrine, a recognized inhibitor of the activation of clotting Factor XII, and depletion of kininogen by administration of carrageenin blocked collagenase-induced oedema. Collagenase did not increase permeability of rat skin vessels, nor did it release potential inflammatory mediators, such as bradykinin or prostaglandins, from plasma or platelets. Bacterial collagenase-induced haemorrhage presumably resulted from enzymatic destruction of membranous structures; at least a portion of the inflammatory response may be due to activation of a kinin-like system.
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PMID:Haemorrhagic and inflammatory properties of collagenase from C. histolyticum. 18 2

More than 90 percent of the cells isolated from the mammary gland of lactating rats with 0.1 percent collagenase were viable by dye exclusion. Myoepithelial cells comprised about one-third of the mammary cells and appeared to be morphologically intact in electron micrographs. [(3)H]Oxytocin-binding activity was localized in an enriched myoepitheial cell fraction obtained by density gradient centrifugation of the isolated cells. The amount of [(3)H] oxytocin bound at 20 degree C and pH 7.6 was proportional to the concentration of oxytocin and the number of cells, reaching a steady state by 40 min. About 0.45 fmol of oxytocin were bound per 10(6) cells. There was a single class of independent binding sites with an apparent K(d), estimated from equilibrium conditions, of 5 nM. This value agrees within experimental error with the value calculated from the ratio of reverse to forward rate constants (5.8 x 10(-4)s(-1) and 2.2 x 10(5) M(-1)s(-1), respectively), consistent with a single-step model for the interaction of oxytocin with binding sites on the cells. Erythrocytes bound only 3.5 percent of the amount of oxytocin bound by an equal number of mammary cells. Oxytocin analogues competed with [(3)H]oxytocin for binding sites in the following order: [deamino]oxytocin > [4-threonine]oxytocin > oxytocin > [O- methyltyrosine]oxytocin > [8-lysine]vasopressin; [lysine]-bradykinin and [4-proline]oxytocin were not inhibitory in the dose ranges tested. These results demonstrate that isolated mammary cells possess oxytocin receptors with properties comparable to those found in broken mammary cell preparations.
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PMID:Binding of [3H]oxytocin to cells isolated from the mammary gland of the lactating rat. 19 65

Renal gluconeogenesis was studied in suspended tubule fragments isolated by collagenase treatment of rat kidney cortices. Angiotensin II increased glucose formation from pyruvate, lactate, and to a lesser extent from oxoglutarate and glutamine, but not from other substrates such as malate, succinate, dihydroxyacetone or fructose. Stimulation was significant with peptide concentration exceeding 1 . 10(-8) M and was also shown with an 8-Sar derivative. Other peptides such as 4-Ala-8-Ile-angiotensin II, hexapeptide and bradykinin had no effect. The stimulatory action of angiotensin II was additive to that of L-lysine, and 3',5'-adenosine cyclic monophosphate, suggesting a different mechanism of action. In the presence of maximally stimulatory concentrations of oleate, phenylephrine and 3',5'-guanosine cyclic monophosphate, however, the stimulatory effect of angiotensin II was absent. Cyclic GMP levels, however, did not increase in tubules after angiotensin II and phenylephrine addition, making a messenger function of this nucleotide unlikely. Omission of Ca2+ from the medium markedly reduced basal gluconeogenesis but did not result in a complete loss of angiotensin II effect. Reduction of medium potassium to 2 mM, however, increased basal gluconeogenesis and blunted the peptide effect. 1 mM ouabain was also able to inhibit the stimulatory effect of angiotensin II. Therefore changes in intracellular potassium levels are discussed as a possible mechanism of angiontensin action, whereas calcium seems not to be specifically linked to this metabolic action of angiotensin on the proximal tubule.
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PMID:Stimulation of renal gluconeogenesis by angiotensin II. 45 78

The endothelium regulates smooth muscle tone in blood vessels through the release of endothelium-deprived relaxing factor (EDRF). We hypothesized that the lymphatics possess endothelium-dependent relaxant properties analogous to those in blood vessels. Fresh porcine tracheobronchial lymphatic vessel rings were mounted in organ baths and connected to force-displacement transducers. Rings were submaximally precontracted with 10(-5) M histamine and exposed to cumulative addition of acetylcholine (ACH; 10(-7)-3 x 10(-4) M) or bradykinin (BRD; 10(-8)-3 x 10(-6) M), both of which are known to promote release of EDRF. ACH caused concentration-dependent relaxation (maximum effect = -2.3 +/- 2.6% of initial histamine-induced active tension), while a similar but less pronounced effect was seen with BRD (39.6 +/- 5.4%). The relaxant effects of ACH and BRD were inhibited by collagenase pretreatment and mechanical endothelial denudation. The results confirm our hypothesis that lymphatic vessels possess endothelium-dependent relaxant properties and suggest that lymph vessels can regulate lymph flow through processes similar to those found in blood vessels.
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PMID:Modulation of lymphatic smooth muscle contractile responses by the endothelium. 131 82

An endopeptidase was purified to homogeneity from the cell extracts of Treponema denticola ATCC 35405 (a human oral spirochete) by a procedure that comprised dialysis, anion exchange fast protein liquid chromatography (FPLC), hydroxylapatite FPLC, immobilized metal affinity FPLC, FPLC chromatofocusing, and two consecutive gel permeation FPLC steps. The enzyme is a 62-kDa protein with an isoelectric point of 6.5-7.0. Experiments with enzyme inhibitors suggest that this enzyme is a metallopeptidase and that its activity is not dependent on sulfhydryl or serine residues. The enzyme is active on furylacryloyl-Leu-Gly-Pro-Ala (FALGPA; pH optimum near 6.25), bradykinin (Bk), and several Bk-related peptides. In FALGPA, the cleavage site is the Leu-Gly bond. An imino acid is absolutely necessary in position P'2. The shortest hydrolyzed peptide was FALGPA, the hydrolysis of which is strongly and competitively inhibited by Bk (Ki = 5.0 microM). The pyrophosphate ion and phosphoramidon also inhibited the hydrolysis of FALGPA. The enzyme does not hydrolyze all typical synthetic collagenase substrates, Azocoll, Azocasein, or Type I and Type IV collagens, or any other proteins tested. In Bk-related peptides, the hydrolyzed bond was Phe5-Ser6. Since a Bk antagonist and a Bk-potentiating pentapeptide also were good substrates, it is possible that the enzyme hydrolyzes Bks and related peptides only because of the coincidental, specific amino acid sequence of those substrates. A proposal is made that since a substantial portion of the amino acid sequence of FALGPA is present in collagen (and additionally acknowledging that the furylacryloyl residue structurally resembles that of proline), the natural substrates of this enzyme may be small, soluble collagen fragments produced by other enzymes from periodontal connective tissue, and that such peptides are important for the nutrition and pathogenicity of T. denticola.
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PMID:Purification and substrate specificity of an endopeptidase from the human oral spirochete Treponema denticola ATCC 35405, active on furylacryloyl-Leu-Gly-Pro-Ala and bradykinin. 132 Nov 41

Tryptase from human mast cells has been shown (in vitro) to catalyze the destruction of fibrinogen and high-molecular-weight kininogen as well as the activation of C3a and collagenase. Although large amounts of tryptase are released in tissues by degranulating mast cells and levels as high as 1000 ng/ml have been measured in the circulation following systemic anaphylaxis, no specific physiologic inhibitor has yet been found for the protease. The current work tests several more inhibitors for their effects on tryptase and examines any effect of tryptase on these inhibitors. First, antileukoprotease and low-molecular-weight elastase inhibitor from human lung and hirudin and antithrombin III had no effect on tryptase activity in vitro. Second, the possibility that tryptase, being insensitive to the effects of inhibitors, might instead destroy them was also considered. Tryptase failed to cleave and inactivate antileukoprotease, low-molecular-weight elastase inhibitor, alpha 1 protease inhibitor, alpha 2 macroglobulin, and antithrombin III. Third, based on the knowledge that tryptase stability is regulated by its interaction with heparin, antithrombin III was used as a model heparin-binding protein to demonstrate that a protein competitor for heparin-binding sites, presumably by displacement of tryptase, destabilizes this enzyme. Conversely, tryptase, in excess, blocked the binding of antithrombin III to heparin, thereby attenuating the heparin-mediated inhibition of thrombin by antithrombin III.
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PMID:Interactions of human mast cell tryptase with biological protease inhibitors. 168 95

Recent reports suggesting that the actions of certain neuroenteric peptides may be mediated in part by the secretion of histamine and other mast cell contents could have important implications for gastrointestinal motility and secretion. However, evidence for a mast cell-hormonal interaction is based on studies using peritoneal or cutaneous mast cells. Because intestinal mucosal mast cells (MMC) differ functionally from peritoneal mast cells (PMC), we compared the effects of several neurotransmitters and intestinal hormones on histamine secretion from two mast cell types in the rat. MMC hyperplasia was induced in rats by infection with the nematode Nippostrongylus brasiliensis, and MMC were isolated from the small intestine by collagenase digestion. Substance P, somatostatin, vasoactive intestinal polypeptide (VIP), neurotensin, and bradykinin had a potent secretagogue effect on (10(-7) to 10(-4)M) PMC which was temperature-, energy-, and calcium-dependent. In contrast to PMC, MMC released significant amounts of histamine only when challenged with substance P. Acetylcholine, bombesin, motilin, and pentagastrin had no secretory effect on either PMC or MMC. The differences between PMC and MMC in responsiveness to peptides could not be attributed to the MMC isolation procedure because PMC treated similarly or mixed with MMC suspensions retained their responsiveness to these stimuli. Our results extend the concept of neurocrine control of mast cell function, but indicate that mast cells from different sites have distinct profiles of responsiveness to regulatory peptides.
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PMID:Mast cell heterogeneity: effects of neuroenteric peptides on histamine release. 240 46

The effect of collagen degradation products by bacterial (BCDP) and synovial fluid collagenase (SCDP) on histamine release from peritoneal mast cells of rat was estimated. Some BCDP as well as SCDP released 60-80% of mast cell histamine. In BCDP fraction the most active were BCDP II (m.wt. 13 kD) and BCDP III (m.wt. 6 kD). The last contained the highest percentage of hydroxyproline. As compared with bradykinin, BCDP III was about 50 fold more active as histamine releaser.
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PMID:Collagen-derived peptides release mast cell histamine. 242 89

To study the nature and extent of mast cell heterogeneity within a single species, we have developed methodologies to isolate rat lung mast cells (LMC) and have compared these to peritoneal mast cells (PMC) and intestinal mucosal mast cells (IMMC). In normal and athymic nude (rnu/rnu) rats, a single intratracheal administration of bleomycin (5 U/kg) leads to pulmonary fibrosis accompanied by parenchymal hyperplasia of mast cells that are histochemically like PMC rather than IMMC. Using collagenase digestion of fibrotic rat lungs (30-80 days after bleomycin treatment), we recovered an average of 58.1 x 10(6) viable cells per rat, containing 2.5% mast cells. Control experiments in which PMC were subjected to the isolation procedure used for LMC showed that there was no qualitative effect on PMC, but that a reduction of 26-60% in responsiveness to secretagogues occurred. Isolated LMC secreted histamine in response to 48/80, A23187, substance P, VIP and somatostatin and bradykinin, but at lower levels than PMC. The anti-allergic compound theophylline, which does not inhibit antigen-induced histamine secretion by IMMC, was effective against both LMC and PMC. Taken together, the thymus independence of pulmonary mast cell hyperplasia, the histochemical characteristics and the responsiveness to secretagogues and anti-allergic compounds indicate that the majority of dispersed LMC are similar to PMC rather than to IMMC. Whether LMC should be considered analogous to PMC or, because of their size, histamine content and responsiveness to many secretagogues, intermediate between PMC and IMMC, remains to be determined through additional studies.
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PMID:Isolation and characterization of lung mast cells from rats with bleomycin-induced pulmonary fibrosis. 246 79

The influence of the endothelium on pulmonary venular responses to reduced oxygen tension has not been defined. To examine this question, endothelial injury was induced in small guinea pig pulmonary artery and venule segments (effective lumen radius, 174 +/- 5 and 122 +/- 2 microns, respectively) by perfusion with either a mixture of hypoxanthine (5 mM) and xanthine oxidase (0.05 U/ml) (HX/XO) or collagenase (2 mg/ml). HX/XO significantly (p less than 0.05) reduced the relaxation of precontracted pulmonary arteries by acetylcholine (ACH), bradykinin (BK), and A-23187, and the relaxations were restored by including superoxide dismutase (40 micrograms/ml) in the HX/XO solution. However, neither HX/XO nor collagenase affected vasodilation induced by ACH, BK, and A-23187 in precontracted pulmonary venules. In contrast, HX/XO significantly (p less than 0.05) augmented the sustained contraction of pulmonary venules to hypoxia (HX/XO, 3.2 +/- 1.0 mg/mm; control, 1.0 +/- 0.5 mg/mm) and anoxia (HX/XO, 35.1 +/- 6.6 mg/mm; control, 20.3 +/- 4.0 mg/mm). Collagenase also significantly (p less than 0.05) enhanced the anoxic contractions (collagenase, 36.0 +/- 3.7 mg/mm; control, 20.9 +/- 6.8 mg/mm). Superoxide dismutase (40 micrograms/ml) and catalase (323 micrograms/ml) abolished HX-XO-induced augmentation of the hypoxic and anoxic contractions of pulmonary venules. Collagenase removed 54 +/- 8% of the venular endothelium (control, 5 +/- 1%), whereas HX/XO-exposed endothelial cells contained numerous craters. Neither gossypol (5 microM) nor methylene blue (10 microM) affected pulmonary venular contractions to reduced PO2. Endothelial damage augments the PO2-dependent contractions of the pulmonary venule, and this augmentation does not appear to be due to decreased release of endothelium-derived relaxing factor.
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PMID:Effect of endothelial injury on the responses of isolated guinea pig pulmonary venules to reduced oxygen tension. 254 70


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