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)

This study was designed to determine changes in one metabolic function, gluconeogenesis (GLG), after ischemic renal injury. Tubule suspensions were prepared by collagenase treatment of SD rat kidneys on 1, 3, and 7 days after left renal artery and vein occlusion for 0-90 min and incubated in Krebs-Henseleit buffer with or without 2 mM pyruvate or malate aerobically. Glucose contents were assayed photometrically. On days 1 and 3 after ischemia for longer than 60 min, serum creatinine levels rose significantly. The tendency of increase of GLG was observed on days 1 and 3 after 10-60 min of ischemia. GLG increased significantly on day 1 after 30-min ischemia. On the other hand, GLG decreased significantly on day 1 after 90-min treatment. Morphologic damage was limited to the corticomedullary region on days 1 and 3 after ischemic times of 30 and 60 min. These results suggest that renal GLG is stimulated to supply energy for ATP decrease by ischemia and for further regeneration in extraproximal segments along the nephron.
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PMID:Alterations of gluconeogenesis by ischemic renal injury in rats. 146 98

A number of cells, chemotactic factors, and inflammatory mediators are implicated in the complex mechanisms underlying crystal-mediated inflammation. Interleukin-8, released from mononuclear cells that have been exposed to urate and other crystals, is a potent chemotaxin and activator of neutrophils. Experimental and clinical observations suggest that joint movements, local biomechanical factors, and previous joint damage may play a role in influencing the intensity of microcrystalline synovitis and the distribution of articular and periarticular crystal deposits in both calcium pyrophosphate dihydrate crystal deposition disease and gout. There are rare reports of extra-articular calcium pyrophosphate dihydrate crystal deposition in tendons, bursae, dura mater, and ligamentum flavum (with radiculomyelopathy) and of massive "tumoral," tophuslike, periarticular calcium pyrophosphate dihydrate crystal deposits. Synovial fluid levels of ATP, the main substrate for nucleoside triphosphate pyrophosphohydrolase ectoenzyme, which cleaves ATP-releasing inorganic pyrophosphate, are higher in patients with calcium pyrophosphate dihydrate crystal deposition disease than in those with other arthritides, and the levels correlate with inorganic pyrophosphate concentrations. Further reports of acute calcific periarthritis of the first metatarsophalangeal joint (hydroxyapatite pseudopodagra) in young women have been described. The mitogenic response of fibroblasts to stimulation with basic calcium phosphate crystals is accompanied by induction and secretion of collagenase and neutral proteases, implicating a role for the crystals in the pathogenesis of both synovial proliferation and joint damage in chronic basic calcium phosphate crystal-associated arthropathy. Subcutaneous cholesterol crystal deposition with tophus formation is extremely rare and has been described in a patient with scleroderma and calcinosis cutis.
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PMID:Calcium pyrophosphate crystal deposition disease and other crystal deposition diseases. 150 84

The nature of K exit across the basolateral membrane of rabbit cortical thick ascending limb (CTAL) was investigated using the patch clamp technique. The basolateral membrane was exposed by mild collagenase treatment (0.1 U/ml), and a K-selective inwardly rectifying channel was identified. In cell-attached patches (140 mM K pipette) the inward conductance was 35.0 +/- 1.3 pS (n = 9) compared with an outward conductance of 7.0 +/- 0.9 pS (n = 5), and the current reversed at a pipette potential of -63.5 +/- 3.1 mV (n = 9). The channel is strongly voltage dependent, showing an e-fold increase in open probability per 18-mV depolarization. Barium blocked the channel, reducing both mean open probability and single-channel current amplitude; however, the channel was not Ca sensitive. On excision the channel exhibited rundown, which could not be prevented by 0.1 mM ATP or ATP plus 20 U/ml catalytic subunit of protein kinase A. A few excised patch recordings were possible, which confirmed the presence of a highly K-selective channel with a K-to-Na permeability ratio of 100. In conclusion, 1) it is possible to obtain patch clamp recordings from the rabbit CTAL basolateral membrane using a very mild collagenase treatment, and 2) the exit of K across the basolateral membrane is mediated at least in part by the presence of voltage-sensitive K channels.
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PMID:Basolateral membrane potassium channels in rabbit cortical thick ascending limb. 151 Jan 23

We measured phosphatidylcholine secretion and its response to surfactant secretagogues in type II cells from developing rats. Cells were isolated from fetal rats on day 21 of gestation by digestion with collagenase and trypsin and purification by differential adhesion. Cells were isolated from adult and postnatal rats on days 1, 7, 14, and 30 by elastase digestion and panning on immunoglobulin G-coated dishes. The basal rate of phosphatidylcholine secretion was the same at all ages but there were developmental changes in the response to secretagogues. The response to terbutaline and an adenosine A2 receptor agonist increased from fetal life until day 7 when it reached the level of adult cells. Adenosine deaminase did not increase the response of the cells to these agonists until day 30, suggesting that the adenosine A1 receptor inhibiting secretion does not become functional until that age. The response to 12-O-tetradecanoylphorbol 13-acetate was lower in the fetal cells but had reached the adult level by day 1. The developmental increase in the response of the cells to ATP was more prolonged with the maximum response not being attained until day 30. With the exception of day 30, when the response to most of the secretagogues was very high, the response to ionomycin was the same at the other ages. These data suggest differential maturation of the signal-transduction pathways mediating surfactant secretion in type II cells.
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PMID:Ontogeny of surfactant secretion in type II pneumocytes from fetal, newborn, and adult rats. 155 Feb 57

The addition of norepinephrine, epinephrine, or forskolin to collagenase-dispersed rat liver hepatocytes increase cAMP and result in a 15% loss in total cell Mg2+ within 5 min. Conversely, carbachol and vasopressin induce a 10-15% increase of total cell Mg2+. Permeabilized hepatocytes also mobilize a large pool of Mg2+ when stimulated by ADP or cAMP. This stimulation is completely inhibited by atractyloside and bongkrekic acid, two different specific inhibitors of the mitochondrial adenine nucleotide translocase. cAMP directly mobilizes Mg2+ efflux from isolated rat liver mitochondria. 50 nM cAMP or 250 microM ADP induces in 5 min a mitochondrial loss of about 6 nmol of Mg2+/mg of protein and a stimulation of ATP efflux. The effect of cAMP is specific, is not reproduced by other cyclic or noncyclic nucleotides, and is inhibited by inhibitors of the adenine nucleotide translocase. These data indicate that cAMP is a messenger for a major mobilization of Mg2+ in hepatocytes. A major target for the effect of cAMP are mitochondria, which lose up to 20-25% of their total Mg2+ in 5 min, both within the cell and after isolation. Evidence is presented suggesting that the adenine nucleotide translocase is the target of the cAMP-dependent Mg2+ efflux and that cAMP may change the operation of the translocase. This, in turn, could change within the matrix the substrate of choice of the translocase from ATP to ATP.Mg.
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PMID:Cyclic AMP-induced Mg2+ release from rat liver hepatocytes, permeabilized hepatocytes, and isolated mitochondria. 166 10

Hydrogen peroxide (H2O2) and hypochlorite (HOCl) cause a variety of cellular dysfunctions. In this study we examined the effects of these agents on the electrical potential gradient across the inner membrane of mitochondria in situ in isolated rat heart myocytes. Myocytes were prepared by collagenase digestion and incubated in the presence of H2O2 or HOCl. Transmembrane electrical gradients were measured by distribution of [3H]triphenylmethylphosphonium+, a lipophilic cation. The particulate fraction was separated from the cytosolic compartment first by permeabilization using digitonin, followed by rapid centrifugal sedimentation through a bromododecane layer. We found that the mitochondrial membrane potential (161 +/- 7 mV, negative inside) was relatively well maintained under oxidant stress, i.e., the potential was decreased only at high concentrations of HOCl and H2O2 and gradually with time. The membrane potential of isolated rat heart mitochondria was affected similarly by H2O2 and HOCl in a concentration- and time-dependent manner. High concentrations of oxidants also reduced the cellular ATP level but did not significantly change the matrix volume. When the extra-mitochondrial free calcium concentration was increased in permeabilized myocytes, the transmembrane potential was decreased proportionally, and this decrease was potentiated further by H2O2. These results support the view that heart mitochondria are equipped with well-developed defense mechanisms against oxidants, but the action of H2O2 on the transmembrane electrical gradient is exacerbated by an increase in cytosolic calcium.
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PMID:Effects of hydrogen peroxide and hypochlorite on membrane potential of mitochondria in situ in rat heart cells. 166 37

The collagen of a primitive invertebrate, the sea-pen Veretillum Cnidaria, Octocorallia), was studied with respect to its molecular-chain composition. The soft extracellular tissues (mesoglea) were solubilized by limited pepsin proteolysis and the collagen was isolated by selective precipitation at 0.7 M NaCl under acidic conditions. The pepsinized molecules were 260 nm in length, as demonstrated by electron microscope studies of rotary-shadowed molecules and of the segment-long-spacing crystallites obtained by dialysis against ATP. SDS/PAGE of the extract produced two main bands susceptible to bacterial collagenase, designated as the alpha 1 and alpha 2 chain, which were differentiated clearly by their CNBr cleavage products and the higher glycosylation rate of the alpha 2 chain. The latter finding corresponds with the high hydroxylysine content of the alpha 2 chain. The alpha 1/alpha 2 chain ratio observed in SDS/PAGE and the fact that only one peak was obtained by concanavalin-A affinity chromatography of a non-denatured 0.7 M NaCl extract demonstrate the alpha 1 [alpha 2]2 molecular structure of this collagen. These results contrast with data on the structure of other coelenterates (i.e. [alpha]3 for sea anemone collagen molecules and alpha 1 alpha 2 alpha 3 for jellyfish collagen molecules). They are discussed in relation to the evolution of collagen.
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PMID:Characterization of heterotrimeric collagen molecules in a sea-pen (Cnidaria, Octocorallia). 173 Feb 24

Hexoprenaline, a beta-adrenergic agonist of clinical importance in preventing preterm labor, and the calcitonin gene-related peptide (CGRP) that is known to have receptors in the plasmalemma of myometrial cells were investigated to ascertain whether in human myometrium K+(Ca++)channels are involved in the relaxant mechanism. Small sections from the fundus and the corpus of vaginal-dissected uteri were isolated under limitation of the operation collective (age of women 35-50 years). Strips of 1-cm length were cut for isometric measurement of contraction. After an equilibration of 60 min under 10 mN tension at 37 degrees C, spontaneous activity occurred and experiments were performed. By enzymatic disaggregation with papain and collagenase single cells were isolated. Electrophysiological experiments were performed using the patch-clamp technique in the cell-attached and excised inside-out configurations. We observed K+ channels with a conductance of 158 pS between -20 and 20 mV in [K+]o/[K+]i of 5.4/140 mM with a reversal potential at about -70 mV. The channel was sensitive to the free calcium concentration on the cytoplasmic side and open probability (Po) increased with membrane depolarization. 0.5 mM ATP facing the cytoplasmic side of the patches (at 40 mV depolarization and pCa of 6) showed no inhibition. Hexoprenaline and CGRP both increased the Po of the K+ (Ca++)channels in the cell-attached mode at steady-state kinetics. Forskolin failed to be an activator of K+ (Ca++)channels. In isometric measurements of human myometrial strips spontaneous activity is suppressed by hexoprenaline 10(-5) M and CGRP 10(-7) M, but these effects are antagonized by 2 mM TEA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Potassium channels and modulating factors of channel functions in the human myometrium. 179 17

The sequence of Escherichia coli UvrA protein suggests that it may fold into two functional domains each possessing DNA binding and ATPase activities. We have taken two approaches to physically isolate polypeptides corresponding to the two putative domains. First, a 180 base pair DNA segment encoding multiple collagenase recognition sequences was inserted into UvrA's putative interdomain hinge region. This UvrA derivative was purified and digested with collagenase, and the resulting 70-kDa N-terminal and 35-kDa C-terminal fragments were purified. Both fragments possessed nonspecific DNA binding activity, but only the N-terminal domain retained its nucleotide binding capacity as evidence by measurements of ATP hydrolysis and by ATP photo-cross-linking. Together, the two fragments failed to substitute for UvrA in reconstituting (A)BC excinuclease and, therefore, were presumed to be unable to load UvrB onto damaged DNA. Second, the DNA segments encoding the two domains were fused to the beta-galactosidase gene. The UvrA N-terminal domain-beta-galactosidase fusion protein was overproduced and purified. This fusion protein had ATPase activity, thus confirming that the amino-terminal domain does possess an intrinsic ATPase activity independent of any interaction with the carboxy terminus. Our results show that UvrA has two functional domains and that the specificity for binding to damaged DNA is provided by the proper three-dimensional orientation of one zinc finger motif relative to the other and is not an intrinsic property of an individual zinc finger domain.
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PMID:Isolation and characterization of functional domains of UvrA. 182 51

This study assessed and compared the rate of glucose utilization, activity of the hexose-monophosphate shunt (HMS), and the oxidation of glutamine, lactate, and palmitate in Kupffer (KC), endothelial (EC), and parenchymal liver cells (PC). Cells were isolated by collagenase and pronase digestion followed by centrifugal elutriation. The freshly isolated cells were incubated in the presence of 5 mM glucose, 0.5 mM glutamine, 1 mM lactate, and 0.4 mM palmitate, and the oxidation rate of individual substrates was determined by the measurement of 14CO2 production. Glucose utilization was assessed by detritiation of [2-3H]glucose. Glucose flux through HMS was 2.6, 1.6, and 0.72 nmol.h-1.mg protein-1 in KC, EC and PC, respectively. The oxidation rate of palmitate in PC (3.5 nmol.h-1.mg protein-1) was about twofold greater than in nonparenchymal cells. Glutamine oxidation was 6.1, 4.2, and 2.1 nmol.h-1.mg protein-1 in KC, EC, and PC, respectively. In contrast, oxidation of exogenous lactate by PC (32.1 nmol.h-1.mg protein-1) was about seven- to eightfold greater than by KC or EC. Presence of prevailing lactate concentrations did not inhibit glucose oxidation in these cells, while it attenuated glucose utilization by PC. Our data show that in the presence of a physiological substrate mixture, less than 20% of the ATP generated from exogenous substrates is derived from glycolysis in KC or EC. Oxidation of glutamine and palmitate are the main sources for energy in these cells. In PC, however, lactate and palmitate oxidation is responsible for approximately 90% for the ATP production derived form the oxidation of exogenous substrates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glutamine and fatty acid oxidation are the main sources of energy for Kupffer and endothelial cells. 187 92


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