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)

Since infections with Schistosoma mansoni cause marked histopathological changes in the liver of the host, the effect of this infection on the hepatic drug-metabolizing function was investigated. Severity of Schistosomiasis was determined by worm counts, duration of infection, egg counts and liver weight increases. To overcome difficulties in homogenizing the livers of infected animals, preincubation of the squashed tissues with collagenase and hyaluronidase was used to prepare homogenates. Key component enzyme activities of the hepatic microsomal drug-metabolizing enzyme system (NADPH-cytochrome c reductase and cytochrome P-450) as well as the representative drug-metabolism activities (aminopyrine N-demethylase, aniline hydroxylase, and benzpyrene hydroxylase) were measured for the whole liver and found to be markedly reduced. However, the measurement of microsomal marker enzyme activities (cytochrome b5 and glucose-6-phosphatase) showed significant elevation. To obtain more precise information about the effect of the schistosome infection on the hepatic drug-metabolizing enzyme system, the total activities of microsomal drug-metabolizing enzymes were related to the total microsomal marker enzyme activities in the homogenate.
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PMID:Effect of Schistosoma mansoni infection on the hepatic drug-metabolizing capacity of mice. 18 61

A large amount of plasma low density lipoprotein is present in human aortic intima, and this can be removed and measured by electrophoresis directly from the minced tissue into an antibody-containing gel. We now find that, in addition to this electrophoretically mobile lipoprotein, there is an immobilized lipoprotein fraction than can be released from lesions by incubation of the tissue sample with plasmin or other proteolytic enzymes after the mobile lipoprotein has been removed. The concentration of immobilized lipoprotein is highly correlated with the concentration of the residual cholesterol (not mobile on electrophoresis) that has accumulated in the tissue (r = 0.702; P less than 0.001). Thus, in normal intima and early gelatinous lesions it is about 15% of the concentration of mobile lipoprotein, whereas in the atheroma lipid layers of fibrous or gelatinous plaques it may be 2 or 3 times greater than the concentration of mobile lipoprotein. This suggests that immobilization of plasma lipoprotein is an intermediate step in the irreversible deposition of extracellular cholesterol in atherosclerotic lesions. Incubation with plasmin allowed maximum release of lipoprotein: plasmin = crude collagenase greater than trypsin greater than "pure" collagenase greater than chondroitinase ABC in order of their relative effectiveness. The concentration of immobilized lipoprotein was significantly correlated (r = 0.793; P less than 0.001) with the concentration in the tissue of fibrin or other insoluble derivatives of fibrinogen ("fibrin"). In aliquots of lesions incubated with varying amounts of plasmin for varying times there was a constant relation between release of lipoprotein and release of fibrin-degradation products. Together, these findings suggest that the lipoprotein is associated with insoluble "fibrin". This appears to be of considerable clinical interest, suggesting a synergism between lipoprotein and fibrinogen in the accumulation of lipid in lesions.
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PMID:The release of an immobilized lipoprotein fraction from atherosclerotic lesions by incubation with plasmin. 18 79

Experiments were performed to indentify the series elastic component (SEC) in intact dog carotid artery held at in situ length. The vessels were studied during excitation of the muscle with norepinephrine and after metabolic poisoning with potassium cyanide and sodium iodoacetate. Static circumferential stress-strain curves and stress-quick-release stiffness curves were examined to evaluate Maxwell and Voigt model elements. The vessels were studied at 33, 36, and 39 degrees C. Temperature variations altered active stress, but did not alter connective tissue properties or the Maxwell SEC stiffness. The Voigt model SEC stiffness was altered, but this was secondary to changes in active stress. Thus, most of the SEC is separate from the contractile apparatus. Other vessels were treated with elastase, collagenase, or hyaluronidase to digest the connective tissue components of the wall. Hyaluronidase had no effect on mechanics. Elastase and collagenase altered connective tissue properties, but only elastase unequivocally altered SEC stiffness. This analysis indicated 1) that the carotid artery wall is better represented by a Maxwell model than a Voigt model, and 2) that the SEC in intact carotid artery is primarily elastin.
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PMID:Identification of smooth muscle series elastic component in intact carotid artery. 19 Aug 98

A number of enzymatic methods have been developed to prepare hepatocytes using collagenase and hyaluronidase. However, best cell preparations are obtained by using only low concentrations of collagenase and exposing the liver to the enzyme for a very short period of time. These isolated cells with intact cell membranes and large numbers of microvilli on the cell surface respond to hormones at physiological concentrations suggesting that these microvilli contain hormone receptors. In addition, high glycogen content is essential to maintain the in vivo metabolic characteristics of the hepatocytes suggesting that intracellular glycogen plays an important role in the hormonal regulation of metabolism in hepatocytes. Studies with glucagon and insulin on carbohydrate metabolism show that the molar ratios of these hormones control gluconeogenesis and glycogenolysis. Furthermore, in vitro addition of insulin stimulates glycogen synthesis and activates glycogen synthase. Insulin also stimulates protein synthesis in cells containing high glycogen and maintains more normal parallel strands of polyribosomes. Studies with isolated hepatocytes from diabetic, hypophysectomized and adrenalectomized animals show a reduced glucagon response to glycogenolysis. This lack of glucagon response was not due to reduction in glycogen levels. Other hormones such as somatostatin and parathyroid also give rise to alterations in carbohydrate metabolism in isolated hepatocytes.
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PMID:Studies of hormonal regulation of metabolism using isolated hepatocytes. 19 66

The influence of previous digestion of cartilage proteoglycans and collagen on cartilage resorption in implants was studied. After implantation for 1, 2, 3, and 4 weeks the morphology of the implants was studied by light microscopy. It was found that enzymatic treatment of cartilage with hyaluronidase, collagenase as well as the combination of both enzymes slightly increased the resorption by granulation tissue. From these studies it can be concluded, that cartilage depletion of proteoglycans facilitates cartilage degradation, however it is not the only reason for the severe cartilage destruction seen in arthritic joints.
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PMID:[Disintegration of enzymatically pretreated cartilage after subcutaneous implantation]. 20 32

An investigation was conducted on the effect of formocresol treatment of the aqueous extractability and enzymatic susceptibility of excised implant tissue. The treated tissue demonstrated a decreased solubility and a diminished digestibility by trypsin, pepsin and collagenase. However, its reactivity toward hyaluronidase showed little alteration.
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PMID:The effects of formocresol on rat sponge implant tissue: a biochemical study. 20 Jun 37

Rat cardiac muscle was dissociated into single cells by a coronary perfusion technique with collagenase and hyaluronidase in a Ca-free medium. Retention of the cylindrical shape of isolated muscle cells could be achieved by regulation of [Ca2+]0 and temperature. Cells kept at 4 degrees C, and 0-01 mM CaCl2 remained cylindrical for more than a week and contracted spontaneously upon warming at 37 degrees C. At [Ca2+]0 between 0-1-2 mM and 37 degrees C, cells underwent contracture and rounded up. Scanning (SEM) and transmission electron microscopy were used to analyze the structure of cylindrical and rounded muscle cells. The extracellular aspect of the sarcolemma at lateral cell surfaces and intercalated disc regions were clearly revealed for SEM analysis. Both the distribution and number of T-tubule openings on the surfaces can be estimated and a three-dimensional description of the intercalated disc obtained. This study reveals that isolated adult heart cells are extremely sensitive to [Ca2+]0, but with careful control of this cation, this preparation should be helpful in the analysis of both sarcolemmal structure and the pathological changes which accompany myocardial injury.
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PMID:Studies of isolated adult rat heart cells: the surface morphology and the influence of extracellular calcium ion concentration on cellular viability. 20 Oct 46

Preneoplastic mammary nodule lines D1, D2, and C4 were enzymatically dissociated with collagenase, hyaluronidase, and pronase or with only collagenase and hyaluronidase to produce high yields of viable single cells; 10(5) cells were injected into the cleared mammary fat pads of syngeneic BALB/cCrgl mice. In 11 experiments involving three different preneoplastic nodule lines with different tumor potentials, all dissociated nodule cell lines showed a marked increase in tumorigenicity as compared to the same tissues transplanted as 1-mm3 pieces. The results could not be explained on the basis of differences between the amounts of cells transplanted in the two procedures. In a second series of experiments, normal mammary cells from virgin, pregnant, or lactating mice were mixed in different ratios with 10(5) nodule cells and injected into the mammary fat pads. The presence of normal cells reversed the marked increase in the tumorigenicity of enzymatically dissociated nodule cells to a level equal to or less than the tumorigenicity of control transplants (1-mm3 pieces). The growth of 10(5) mammary tumor cells was not inhibited when tumor cells were mixed with 3 x 10(5) normal cells and transplanted into the mammary fat pads. These results showed that enzymatic dissociation can lead to an increase in tumor potential of preneoplastic mammary nodule lines, and they supported the hypothesis that nodule cells, but not neoplastic cells, are sensitive to the growth-inhibitory effects of normal mammary cells.
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PMID:Enhancement of the tumorigenicity of preneoplastic mammary nodule lines by enzymatic dissociation. 20 61

Inapparent nodule-transformed cells were recovered from morphologically normal mammary tissue from virgin female BALB/cfC3H/Crgl (mouse mammary tumor-positive) mice before the appearance of hyperplastic alveolar nodules (HAN) or tumors, by means of the cell dissociation technique. Mammary tissues were dissociated by means of collagenase (0.1%), hyaluronidase (0.1%), and pronase (1.25%). Aliquots of 10(5) viable cells in 0.01 ml medium were injected into the gland-free mammary fat pads of 3-week-old female syngeneic mice. After 10 weeks the outgrowths were examined and classified as ductal, HAN, tumor, or combinations of these types. The presence of HAN outgrowths indicated the presence of nodule-transformed cells in the donor mammary tissues. Nodule-transformed cells were recovered from 2-month-old donors, and the number of HAN outgrowths increased with donor age. Overt HAN and tumors did not appear in virgin female BALB/cfC3H/Crgl mice younger than 8 to 9 months of age. The data suggest that inapparent nodule-transformed cells occurred long before the appearance of HAN of tumors and that the numbers of transformed cells increased with donor age.
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PMID:Detection of inapparent nodule-transformed cells in the mammary gland tissues of virgin female BALB/cfC3H mice. 20 23

Improved methods for preparation from primitive streak chick blastodiscs of cell suspensions capable of forming erythroid cells in culture have been developed. When blastodiscs were preincubayed with hyaluronidase in the absence of collagenase before cell dispersion and a high concentration of methyl-alpha-mannoside was present in all media, the yields of cells were some 10-fold higher than those obtained by former procedures. Cell suspensions obtained consisted almost entirely of viable cells, yielded large numbers of free mature erythrocytes in liquid culture, and formed erythroid colonies and bursts in solidified medium. The capacity to form differentiated cells after resedimenrtation through Ficoll density gradients was partly stabilized. Addition of gee yolk homogenate to the blastodiscs immediately following treatment with hyaluronidase and to all media used thereafter largely stabilized the capacity to form erythroid cells during resedimentation through Ficoll density gradients. Possible relevance of observations made during development of the procedures to the control of onset of cell migration in the process of gastrulation is indicated.
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PMID:Preparation of cell populations with stabilized erythropoietic potential from the primitive streak chick blastodisc: some implications for control of gastrulation. 20 27


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