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)

An LH-responsive Leydig cell preparation (containing 6+/-2% Leydig cells) was obtained by collagenase treatment of rat testis. Centrifugation of this cell preparation through a 13% Ficoll solution for 10 min at 1500 g resulted in a four times purification of the Leydig cells, with a concomitant increases in steroidogenic activity. Addition of 0-2% albumin to the 13% Ficoll solution, adjusted to 280 mosmol/l, resulted in a further twofold purification of the Leydig cells paralleled by a twofold increase in steroidogenic activity. Centrifugation of these Ficoll-albumin-purified Leydig cells through a 6% dextran solution for 2 min at 100 g resulted in a further 1-7 times purification of the Leydig cells. A combination of the two centrifugation steps resulted in a 12-5 times purification of Leydig cells compared with the original crude cell suspension, while an increase in steroidogenic activity of 22-5 times was obtained. This final cell preparation contained 59 +/- 17% Leydig cells (mean +/- S.D., n = 6). The recovery of Leydig cells was 29%. Collagenase treatment of testes deficient in spermatogenesis resulted in a cell preparation with the same steroidogenic activity as Ficoll-purified cells from normal testes. Centrifugation of these cells through a 13% Ficoll solution gave only a limited increase in the steroidogenic activity. Isopycnic centrifugation of the crude cell preparation on a discontinous Ficoll metrizoate gradient resulted in two discrete peaks of Leydig cells, one peak at a density of 1-039-1-055 g/ml and one at a density of 1-068-1-088 g/ml. Both types of cells produced testosterone. In the presence of LH, cyclic AMP production in both types of Leydig cells increased, but testosterone production was only increased by LH in the "denser" Leydig cells and not in the "light" Leydig cells. No difference in sensitivity to LH could be observed between the Leydig cell preparations of different purity. Using a 60 min pre-incubation period the highest testosterone response was obtained with 100-1000 ng LH/ml. The same maximum testosterone response was obtained with 10-100 ng LH/ml when the pre-incubation period was omitted.
J Endocrinol 1976 Sep
PMID:Purification and characterization of Leydig cells from rat testes. 18 9

The low molecular weight bronchial protease inhibitor isolated from purulent bronchial secretions of man was shown to be a potent inhibitor of the elastase from human granulocytes. At a molar ratio of 1:1, the inhibitor prevented elastase digestion of insoluble elastin and soluble elastin, and blocked the hydrolysis of t-BOC-L-alanine-p-nitrophenyl ester. The collagenolytic activity of granulocyte collagenase was not inhibited by the bronchial inhibitor. Antisera were raised in rabbits for the isolation of specific IgG fractions in order to localize and quantitate the inhibitor. 125I-labelled inhibitor was used to study enzyme interactions further by gel filtration. These studies demonstrated that the bronchial inhibitor formed firm complexes with granulocyte elastase but did not form complexes with granulocyte collagenase.
Scand J Clin Lab Invest 1976 Sep
PMID:Inhibition of elastase from granulocytes by the low molecular weight bronchial protease inhibitor. 18 83

The effect of somatostatin on insulin secretion in response to a variety of stimuli was investigated in micro-dissected as well as collagenase isolated pancreatic rat islets. Somatostatin inhibited insulin secretion in both islet preparations in the presence of different initiators, but failed to affect the hormone output induced by theophylline, 1-methyl-3-isobutylxanthin (IBMX) or p-chloromercuriphenylsulfonic acid (CMBS). The inhibitory action was associated with decreased glucose metabolism by islets (measured as conversion of U-14C-glucose to 14CO2).
Diabete Metab 1976 Sep
PMID:Somatostatin-induced inhibition of insulin secretion by isolated pancreatic rat islets prepared by micro-dissection or collagenase digestion. 18 97

Explants from rabbit aortic media were incubated in MEM medium supplemented with 14C-lysine and with 10 p. 100 hyperlipemic (type IV and V) or normal human serum respectively. The incubated fragments were extracted at increasing ionic strength. The insoluble collagen and elastin were hydrolysed with collagenase and alcoholic potassium hydroxyde respectively. The radioactivity was determined in the extracts and the radioactive labelling profile of proteins was investigated on polyacrylamide gel electrophoresis in SDS. With the exception of the collagenase extract (polymeric collagen) the incorporation of the radioactivity into insoluble collagen is not altered or increases. These the incubation was carried out in the presence of hyperlipemic serum. Incorporation of the radioactivity into insoluble collagen seems not to be altered. These results show a decreased protein synthesis with a relative increase in the biosynthesis of polymeric insoluble collagen in the aortic media incubated in the presence of hyperlipemic serum.
Paroi Arterielle 1976 Sep
PMID:Action of human hyperlipemic sera on the biosynthesis of intercellular matrix macromolecules in aorta organ cultures. 18 73

A method has been developed for the long-term culture of dissociated adult mouse dorsal root ganglia (DRG). Of critical importance to the success of this technique was a three-hour incubation in collagenase which softened the DRG and permitted gentle dissociation. The morphological and electrophysiological features of the dissociated adult DRG were similar to those observed in previous studies of immature (i.e., embryonic and newborn) DRG in culture and also to those of adult DRG in situ. With regard to electrophysiological work, the adult DRG neurons are superior to embryonic and newborn neurons because of their larger size and greatly increased survival in culture (no degeneration for first six days, and thereafter a relatively slow decrease). The adult neurons regenerated nerve fibers to an extent comparable to that of immature neurons. Therefore, the adult DRG cultures might be useful to study factors influencing regeneration in the adult mammalian nervous system. The adult cultures might also be useful to investigated factors influencing the aging process.
J Neurobiol 1977 Sep
PMID:Adult mouse dorsal root ganglia neurons in cell culture. 19 11

The release of acetylcholine from synaptosomal preparations from bovine superior cervical ganglia and rat cortex was inhibited when the preparations were pretreated with collagenase. The inhibition of release could be overcome with the calcium ionophore A23187. Collagenase treatment was shown to inhibit the uptake of calcium into the preparations. In addition, gel electrophoresis of synaptosomal membranes revealed two missing high molecular weight proteins when either synaptosomes or synaptosomal membranes were incubated with collagenase.
Brain Res 1977 Sep 23
PMID:The mechanism of actions of collagenase on the inhibition of release of acetylcholine from synaptosomal preparations. 19 17

In epidermolysis hereditaria bullosa dystrophica increased collagenase activity can be detected and seems to be one of the pathogenetic mechanisms of this disease. Neither the origin nor the mechanism of increased collagenolysis is known. Whether the cause of the enzymatic imbalance is the increased collagenase production or decreased collagenase-inhibitor activity cannot be decided. Factors of decreased protease inhibitor activity could be the quantitative or qualitative defect or the inactivation of the inhibitor. Clear, sterile vesicular fluid was incubated with alpha-1-antitrypsin, which is known to inhibit collagenase. By means of an immunoelectrophoretic method the cleaving of the inhibitor into two antigenic split products was found. We suggest that this might be responsible for the increased collagenolysis in this form of epidermolysis.
Hautarzt 1977 Sep
PMID:[Vesicular fluid of hereditary bullous dystrophic epidermolysis splits alpha 1-antitrypsin]. 19 57

In order to study the role of cyclic AMP in the inhibition by somatostatin of glucose-induced insulin release, the effect of somatostatin on the potentiation by dibutyryl-cyclic AMP (db-cAMP) of insulin release from isolated pancreatic islets of rats was examined. Isolated islets were obtained from the rat pancreas by the collagenase method. Ten islets were incubated for periods of 30 min in Krebs-Ringer bicarbonate buffer containg albumin and glucose 2.0 mg/ml in the presence or absence of somatostatin (1 microgram/ml or 100 ng/ml) and/or db-cAMP 1 mM. Glucose-induced insulin release was reduced by somatostatin in concentrations of 1 microgram/ml. Somatostatin in a concentration of 100 ng/ml significantly abolished the potentiation by db-cAMP of insulin release (p less than 0;01), in spite of exerting no inhibition of glucose-induced insulin release. However, in the presence of theophylline 5 mM, somatostatin 100 ng/ml did not show that inhibitory effect on the potentiated insulin release.
Horm Metab Res 1977 Sep
PMID:Insulin release from collagenase-isolated islets of rat pancreas in the presence of cyclic AMP and somatostatin. 20 May 35

Fluxes of 86Rb+ and hydrolysis of p-nitrophenyl phosphate were measured in collagenase-isolated islets of diabetic C57BL/KsJ-db/db-mice and normal controls (C57BL/KsJ-+/+). Both types of islets accumulated Rb+ avidly, as originally reported for hand-dissected islets of non-inbred ob/ob-mice. KsJ-db/db-mouse islets showed enhanced accumulation of Rb+ and normal activity of K+-activated nitrophenyl phosphatase. D-glucose, 20 mmol/l, inhibited Rb+ efflux in normal islets but not in those from KsJ-db/db-mice. The glucose insensitivity of Rb+ efflux was observed in young animals, which exhibit glucose-induced insulin release, as well as in old animals, which do not secrete insulin in response to glucose. The anomalous regulation of Rb+ efflux already present in young animals may bear on the liability of KsJ-db/db-mouse B-cells to develop defective control of membrane potential, an abnormal metabolism of cyclic AMP, and a marked failure of insulin secretory capacity.
Diabetologia 1978 Sep
PMID:86Rb+ fluxes and K+-stimulated nitrophenyl phosphatase activity in the pancreatic islets of genetically diabetic mice (C57BL/KsJ-db/db). 21 36

Mixtures of epithelial and stromal cells isolated from normal adult rabbit cornea, when cocultured in the presence of cytochalasin B, produced latent collagenase, whereas neither cell type alone, nor the mixture in the absence of this agent, did so. The enzyme, a characteristic animal collagenase, required proteolytic activation. The relative concentrations of epithelial and stromal cells had a profound effect on on collagenase production, the enzyme activity bieng directly proportional to the number of stromal cells but inversely proportional to the number of epithelial cells. The amount of enzyme released into the medium was also directly proportional to cytochalasin B concentration. Media conditioned by cytochalasin B-treated epithelial or stromal cells did not stimulate collagenase secretion by the other cell type. The data suggest direct cell contact or close proximity as the mode of productive interaction and tentatively identify the stromal cell as the source of enzyme and the epithelial cell as a stimulator.
Proc Natl Acad Sci U S A 1978 Sep
PMID:Regulation of corneal collagenase production: epithelial-stromal cell interactions. 21 49


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