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)

Clinically implanted prostheses of biological origin have recently been shown to develop aneurysms within several years. To study this process, recently developed bovine heterografts that were implanted in canine ilio-femoral arteries for 27 to 45 months, were studied in vivo and in vitro. Seven out of seven grafts were patent with only one showing evidence of focal aneurysm. Measurements of mechanical properties, including water permeability, compliance, and burst pressure, and of heat shrink temperature and dry weight were obtained before and after a period of controlled exposure to bacterial collagenase; all data suggested that much of the original graft had been replaced with host tissue. However, enzyme susceptibility was less than that of fresh bovine arteries, indicating that at least some of the grafts' crosslinked collagen was preserved. The compliance of these explants was similar to that reported for autogenous vein. Histological examination of the graft wall revealed cellular "intimal" and adventitial zones containing host-generated collagen surrounding a central zone devoid of cellular infiltration, which appears to be unmodified graft "media" highly resistant to degradation. We conclude that, when properly processed, biological prostheses can act as a bioresorbable scaffold for the orderly replacement of structural elements during healing, promoting continued mechanical integrity of the graft. These promising results encourage the further development of prostheses of biological origin.
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PMID:Longterm study of a compliant biological vascular graft. 203 86

The renal response to changes in hydration includes variation in intracellular sorbitol, a major inner medullary osmolyte. To examine the mechanism for changes in net sorbitol production, we measured activities of enzymes regulating sorbitol production (aldose reductase) and degradation (sorbitol dehydrogenase) in untreated, water diuretic, and antidiuretic (water restriction and/or vasopressin administration) rats. Collecting duct segments dissected from collagenase-treated kidneys of Sprague-Dawley rats were divided into outer medullary and three distinct inner medullary regions. Aldose reductase activity increased during antidiuresis and decreased during diuresis. In contrast, sorbitol dehydrogenase activity was very low during antidiuresis and increased during diuresis. These changes in enzyme activity were found after 3 days, but not after 1 day, of water diuresis/antidiuresis. Enzyme activity changed only in the deepest 50% of the inner medullary collecting duct. Thus, there is coordinated regulation of aldose reductase and sorbitol dehydrogenase activities so that (a) during water diuresis, aldose reductase activity decreases while sorbitol dehydrogenase activity increases; and (b) during antidiuresis (water restriction and/or vasopressin administration), aldose reductase activity increases while sorbitol dehydrogenase activity remains low. We conclude that long-term osmoregulation in response to physiologic stimuli involves both aldose reductase and sorbitol dehydrogenase activities in rat terminal inner medullary collecting duct segments.
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PMID:Coordinated response of renal medullary enzymes regulating net sorbitol production in diuresis and antidiuresis. 212 8

Latent human fibroblast collagenase (HFC) can be activated by a variety of seemingly disparate means. In addition to the well-characterized activation by trypsin and organomercurial compounds, the enzyme can be activated to various extents by surfactants such as sodium dodecyl sulfate, by chaotropic ions such as SCN-, by disulfide compounds such as oxidized glutathione, by sulfhydryl alkylating agents such as N-ethylmaleimide, and by oxidants such as NaOCl. The underlying basis for these activations is the modification, exposure, or proteolytic release of the Cys73 residue from its habitat in the latent enzyme where it is thought to be complexed to the active-site zinc atom. This residue is not accessible for reaction with small molar excesses of dithionitrobenzoate in native, latent HFC. However, on addition of EDTA, this residue becomes fully exposed and is quantitatively labeled. All modes of activation of latent HFC are believed to involve the dissociation of Cys73 from the active-site zinc atom and its replacement by water, with the concomitant exposure of the active site. This is thought to be the primary event that precedes the well-known autolytic cleavages that are observed following the appearance of collagenase activity. The dissociation of Cys73 from the zinc atom in the latent enzyme "switches" the role of the zinc from a noncatalytic to a catalytic one. This "cysteine switch" mechanism of regulation may be applicable to the entire collagenase gene family.
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PMID:Multiple modes of activation of latent human fibroblast collagenase: evidence for the role of a Cys73 active-site zinc complex in latency and a "cysteine switch" mechanism for activation. 215 97

Pediatric liver transplantation is successful but donor scarcity is a major limitation. We are studying hepatocyte transplantation as an alternative to provide functional hepatic replacement. This report details the study of rat liver perfusion for optimal harvest of hepatocytes and cell implantation. We performed 128 rat liver perfusions using a technique modified from the two-step enzymatic perfusion described by Seglen. We examined variations in the perfusion, rate, time, antegrade versus retrograde, pulsatile versus continuous flow, temperature, collagenase type, and variables of buffer composition. We have found optimal cell yield and viability under the following conditions: in situ perfusion, continuous flow at 25 cc/min, retrograde perfusion via the inferior vena cava, water bath temperature 38 degrees C, Boerhinger-Mannheim collagenase using a nonoxygenated HEPES based perfusion buffer, pH 7.4, for the initial perfusion and the same buffer with 4.8 mmol/L CaCl2 for the collagenase perfusion. These conditions consistently generate cell harvests of 500 to 700 x 10(5) cells/g of liver tissue with cell viability between 85% and 95%.
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PMID:Studies in rat liver perfusion for optimal harvest of hepatocytes. 215 93

Skh:HR-1 hairless mice were irradiated chronically with sub-erythemal doses of UVB radiation, and a number of biochemical parameters in the skin were determined after 6, 12, 18, and 24 wk of exposure. The parameters measured were water, collagen, elastin, and glycosaminoglycan content; collagenase and elastase levels; and Bz-Tyr-OEt (N-benzoyl-L-tyrosine ethyl ester) and BAPNA (alpha-N-benzoyl-DL-arginine-p-nitroanilide) hydrolyzing activities. Data for UVB radiation-exposed and chronological age-matched control mice were compared with respect to unit area and to unit mass of skin. On a unit area of skin basis, UVB radiation exposure increased the level of most parameters. The particular exceptions were collagen and collagenase which remained constant. On a mass of skin basis, though, there is an apparent decrease in collagen content because of the increase in the other skin components. This suggests that there is insufficient collagen in UVB radiation-exposed skin to support the increasing mass of the tissue.
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PMID:Chronic ultraviolet B radiation-induced biochemical changes in the skin of hairless mice. 215 30

Intracranial bleeding is an important cause of brain masses and edema. To study the pathophysiology of intracerebral hemorrhage, we produced experimental hemorrhages in 53 rats and characterized the lesion by histology, brain water content, and behavior. Adult rats had 2 microliters saline containing 0.5 unit bacterial collagenase infused into the left caudate nucleus. Histologically, erythrocytes were seen around blood vessels at the needle puncture site within the first hour. By 4 hours there were hematomas, the size of which depended on the amount of collagenase injected. Necrotic masses containing fluid, blood cells, and fibrin were seen at 24 hours. Lipid-filled macrophages were observed at 7 days and cysts at 3 weeks. Water content was significantly increased 4, 24, and 48 hours after infusion at the needle puncture site and for 24 hours in posterior brain sections. Behavioral abnormalities were present for 48 hours, with recovery of function occurring during the first week. Brain tissue contains Type IV collagen in the basal lamina. Collagenase, which occurs in an inactive form in cells, is released and activated during injury, leading to disruption of the extracellular matrix. Collagenase-induced intracerebral hemorrhage is a reproducible animal model for the study of the effects of the hematoma and brain edema.
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PMID:Collagenase-induced intracerebral hemorrhage in rats. 216 Jan 42

A simple technique for the controlled collagenase digestion of the human pancreas is described. The pancreas is distended with collagenase, and a biopsy taken and divided into 5 pieces that are placed in Universals containing minimal essential medium and dithizone at 39 degrees C. The pancreas itself is incubated in MEM at 39 degrees C. Starting at 5 min and at intervals thereafter, a Universal is removed from the water bath, shaken for 30 sec, and the contents examined by microscopy. As soon as free cleaved islets are seen, the pancreas is placed into one compartment of a kidney-bowl divided in half by a 1-mm mesh. The pancreas is gently teased apart and fluid digest in the empty half of the bowl aspirated and passed through a 500-micron mesh into ice-cold MEM containing 20% newborn calf serum. This process is repeated until the digestion process has ceased. Using this technique on 20 consecutive pancreata, median wt. (range) 53.9 (45.2-72.9) g, we have counted 131,672 (43,516-400,000) islets in the digest, equivalent to 2394 (715-8000) islets/g pancreas. The volume of islet tissue in the digest was 299 (26-1341) mm3 equivalent to 5.81 (0.36-26.81) mm3/g pancreas. In conclusion, we have found this simple technique to be an effective method for the controlled collagenase digestion of the human pancreas.
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PMID:A simple method for the release of islets by controlled collagenase digestion of the human pancreas. 216 34

Collagen is present in Porifera, the lowest multicellular animals, but there is no information available on the primary structure of the collagen chains in this phylum. Developing fresh-water sponges have been used to extract total RNA in order to study in vitro translation products and to construct a cDNA library. Four translated proteins were collagenase-sensitive (200 kDa, 160 kDa, 81 kDa and 48 kDa). The cDNA library was screened with a human collagen probe and a clone, EmC4, covering 1.2 kb was isolated. Nucleotide sequencing of EmC4 revealed a conceptual open reading frame coding for 366 amino acids terminated by a stop codon TGA with 103 nucleotides downstream. The presumed translation product encoded contained several domains: a non-collagenous C-terminal domain of 156 amino acids with 9 cysteines, an uninterrupted collagenous domain of 171 amino acids, a non-collagenous domain of 16 amino acids with 3 cysteines and a probably incomplete N-terminal collagenous domain of 23 amino acids. Comparison with other sequences suggested that this collagen chain might belong to a non-fibrillar collagen family which evolved into several sub-families giving rise to nematode cuticular collagens, and type IV collagens.
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PMID:Cloning and sequencing of a Porifera partial cDNA coding for a short-chain collagen. 216 43

In previous studies, elevations in the levels of active and latent collagenase in gingival crevicular fluid (GCF) have been correlated positively with periodontal disease activity. To provide a simple diagnostic approach for testing collagenolytic activity, the feasibility of using a 3.0 ml water mouthrinse to collect GCF simultaneously from all sites in the mouth was assessed. Patients with adult periodontitis (AP, n = 23) and local juvenile periodontitis (LJP, n = 7) were sampled before periodontal therapy and some (12 AP, 4 LJP) were also assessed longitudinally after scaling and root planing, administration of antibiotics, and following periodontal surgery. Healthy patients (n = 19) were used as controls. The levels of active collagenase, procollagenase, and collagenase inhibitor activity were determined by functional assays and quantitated after SDS-PAGE and fluorography. Gelatinase and progelatinase were assayed by enzymography on gelatin-substrate gels. Active collagenase levels were found to be significantly higher (14- to 20-fold) in AP and LJP patients compared to controls, whereas matrix metalloproteinase activity was not detected in mouthrinses from edentulous patients. Collagenase inhibitor levels were generally low in all groups of subjects tested. Following clinical treatment the levels of active collagenase and gelatinase were reduced; the reduction was significant for active collagenase after tetracycline treatment and scaling in LJP patients. Of the clinical indices recorded (gingival index, plaque index, and pocket depth) there were no significant correlations with enzyme activity but similar trends were observed between the changes in active collagenase and gingival index. In patients with untreated periodontal disease, collagenase occurred predominantly in the active form. N-ethylmaleimide (NEM) and p-aminophenylmercuric acetate (AMPA) were equally effective as activators of the latent collagenase, indicating that the collagenase was derived from PMNs, which were also the source of gelatinase. The results of these studies indicate that measurement of active collagenase and gelatinase in mouthrinse samples is potentially useful in the diagnosis and assessment of periodontal disease activity.
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PMID:Identification of polymorphonuclear leukocyte collagenase and gelatinase activities in mouthrinse samples: correlation with periodontal disease activity in adult and juvenile periodontitis. 217 Jun 17

Regulation of urea transport by vasopressin in inner medullary collecting duct (IMCD) cells is thought to be important for the urinary concentrating mechanism. Isolated tubule perfusion studies suggest the existence of a saturable urea carrier. We have measured 14C-urea efflux in IMCD cells which were freshly isolated and grown in primary culture. Cells were isolated from rat papilla by collagenase digestion and hypotonic shock. In suspended cells, 14C-urea efflux (Jurea) from loaded cells was exponential with time constant 59 +/- 3 sec (SEM, n = 6, 23 degrees C). Jurea had an activation energy of 4.1 kcal/mole and was inhibited 42 +/- 7% by 0.25 mM phloretin and 30-40% by the high affinity urea analogues dimethylurea and phenylurea. Jurea was increased 40-60% by addition of vasopressin (10(-8) M) or 8-bromo-cAMP (1 mM); stimulated Jurea was inhibited 55 +/- 8% by the kinase A inhibitor H-8. Phorbol esters and epidermal growth factor did not alter Jurea. IMCD cells grown in primary culture were homogeneous in appearance with greater than fivefold stimulation of cAMP by vasopressin. The exponential time constant for urea efflux was 610 +/- 20 sec (n = 3). Jurea was not altered by vasopressin, cAMP or phloretin. Another function of in vivo IMCD cells, vasopressin-dependent formation of endosomes containing water channels, was absent in the cultured cells. These results demonstrate presence of a urea transporter on suspended IMCD cells which is activated by cAMP and inhibited by phloretin and urea analogues. The urea transporter and its regulation by cAMP, and cAMP-dependent apical membrane endocytosis, are lost after growth in primary culture.
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PMID:Urea transport in freshly isolated and cultured cells from rat inner medullary collecting duct. 217 46


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