Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In untreated patients with inoperable lung cancer, serum levels of alpha1-antitrypsin were found significantly increased in comparison to patients with non malignant diseases of the lung, alpha2-macroglobulin levels were unchanged in both groups of patients. There was also no difference in alpha2-macroglobulins in cancer patients reacting with DNCB and in non-reactors. Thus alpha2-macroglobulin levels do not seem to correlate with the immunestatus of cancer patients. Proteinase inhibitors are involved in a variety of biological processes including blood, clotting, digestion, and sperm capacitation. alpha1-antitrypsin, a alpha-globulin with a molecular weight of about 60,000 has been found to be decreased in patients' serum under several pathological conditions. A clear correlation exists between alpha1-antitrypsin deficiency and hereditary pulmonary emphysema (1, 2), respiratory distress syndrome (3), and juvenile cirrhoses of the liver (4). Elevated serum levels of alpha1-antitrypsin have also been found in some cancer cases. Thirty years ago a cancer test was developed on the basis of differences in the antiproteolytic activity in cancer patients' sera and in patients with other non-neoplastic diseases (5, 6). Several authors have tried to confirm these early data regarding specifity and sensitivity with respect to a screening test for cancer (7, 8). Methods of these authors were based mainly on enzyme substrate inhibition assays by addition of the patients' sera. Recently a commercially available test, based on immune-precipitation according to Mancini (9), has been developed (Behring-Werke, Partigen). By using this standardized method for determinating alpha1-antitrypsin, Harris et al. have recently demonstrated that patients with inoperable lung cancer have significantly elevated levels of this antiprotease in their sera (10), in comparison to patients with non malignant diseases of the lung. alpha2-macroglobulin is a serum protein with a molecular weight of 800,000 and with known antiprotease activity and can therefore bind trypsin, plasmin, elastase, and collagenase and it is known that alpha2-macroglobulin decreases with increasing of age. Changes of alpha-macroglobulin have also been observed in several pathological conditions (11). James et al. 4ave found decreases in serum of myeloma patients (12). An association between the development and function of lymphocytes and alpha2-macroglobulin has been suggested by several authors (13, 14). This alpha2-globulin has also been demonstrated on the surface of peripheral blood lymphocytes (15) and there is evidence that it is synthesized by lymphocytes (16). The purpose of the present study was to determine serum alpha1-antitrypsin levels in patients with inoperable lung cancer and to determine whether there is also an inverse correlation to alpha2-macroglobulin. It was further attempted to correlate alpha2-macroglobulin with general immunological parameters, as it is known that patients with lung cancer show a decreased general immune-reactivity (17).
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PMID:Serum levels of alpha1-antitrypsin and alpha2-macroglobulin in lung cancer. 6 86

GST activities against 1-Chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) were measured in isolated and cultured adult rat hepatocytes. Within 24 h in culture, both GST activities decreased to about 70% and either stabilized at this level (CDNB) or recovered (DCNB) to the initial level. Use of hyaluronidase in addition to collagenase during the isolation of the cells strongly reduced both activities and its stimulation by various drugs for up to 168 h. The hormones insulin, glucagon, triiodothyronine, estradiol, testosterone, and progesterone did not affect GST activity, while dexamethasone showed some interference. In the presence of dexamethasone the activity against CDNB was mainly stimulated by the combination of methylcholanthrene (MC) and phenobarbital (PB) to about 260% within 168 h. The activity against DCNB was stimulated predominantly by MC alone reaching 170% after 168 h. Quantification of the GST subunits Ya, Yb1 and Yp by an ELISA technique revealed a strong decrease of Ya, a transient increase of Yb1 after 24 h followed by a moderate decrease, and a stable low level of the transformation marker Yp during cultivation. The level of Ya was markedly induced by PB, particularly in combination with MC. The level of Yb1 was equally induced by MC or PB with no synergistic effect. Yp was not affected by these drugs. None of the hormones affected the level of these GST subunits. These results indicate that the physiological type of regulation of the GSTs is maintained during primary culture and no signs of dedifferentiation or transformation are observed. Furthermore, they demonstrate that the interaction of drugs and hormones and their inducing potential can be efficiently studied in the cultured hepatocytes.
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PMID:Influence of hormones and drugs on glutathione-S-transferase levels in primary culture of adult rat hepatocytes. 208 92

The preparation of hepatocytes using the two-stage perfusion technique usually involves the use of collagenase (CII) alone or in combination with dispase (C/D) or trypsin inhibitor (CA/TI) as digestion enzymes. The effect of CII, C/D and CA/TI on cell viability, yield, cytochrome P450 mediated oxidation of testosterone, glucuronidation and sulfation of 7-hydroxycoumarin, glutathione content, glutathione-S-transferase activity and glutathione-conjugation capacity of hepatocytes has been assessed. Cytochrome P450 mediated oxidation of testosterone was significantly (p < 0.05) decreased with CII isolated hepatocytes (81.7 +/- 3.3 nmol/10(6) cells, mean +/- S.E.M., n = 3), compared with those isolated using CA/TI (96.6 +/- 1.9 nmol/10(6) cells) or C/D (95.1 +/- 2.1 nmol/10(6) cells). In contrast, glutathione conjugation of the non-specific substrate 1-chloro-2,4-dinitrobenzene was significantly (p < 0.05) increased with CII isolated hepatocytes (56.9 +/- 5.9 nmol/10(6) cells, mean +/- S.E.M., n = 3), compared with those isolated using CA/TI (36.0 +/- 3.7 nmol/10(6) cells) or C/D (31.6 +/- 3.7 nmol/10(6) cells). These findings have significant implications for the interpretation of metabolism data derived from hepatocytes in suspension, particularly in terms of glutathione conjugation of potentially toxic reactive intermediates of xenobiotic metabolism. Indeed, data presented show that the presence of trypsin inhibitor in the preparation of isolated rat hepatocytes significantly affects the formation of glutathione conjugates of reactive intermediate products of troglitazone metabolism.
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PMID:The extent of phase I and phase II reactions is affected by the choice of enzyme used to prepare rat hepatocytes. 1933 Aug 83

Collagen gel sandwich and immobilization cultures of rat hepatocytes are two recently developed organotypical culture models. Basic information with respect to the maintenance of xenobiotic biotransformation pathways and the expression of key enzyme activities, however, is lacking, making their use in pharmaco-toxicological studies rather speculative. The expression of the glutathione S-tranferase (GST; EC 2.5.1.18) activity, a key phase II enzyme, has been chosen to study the various problems that may arise in expressing the results of cytosolic enzyme activities when rat hepatocytes are cultured using both new culture models. Collagen gel matrix easily entraps culture medium proteins. These interfere with the cytosolic protein content, a parameter versus which cytosolic enzyme activities, including GSTs, are usually expressed. The following solutions are proposed: expression of the cytosolic enzyme activity results versus either (i) microsomal proteins, these are not contaminated by medium proteins, or versus (ii) cytosolic proteins after a complete collagenase digestion (0.05% collagenase type I of Sigma, 45 min, 37 degrees C) of the collagen matrix. Expression of enzyme activities versus cellular DNA appears to be unacceptable since unreliable results were obtained due to entrapped DNA in the collagen matrix. Once it was known how to express cytosolic enzyme activity, the maintenance of GST activities was investigated in both culture models using 1-chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) as substrates for total and Mu class GSTs, respectively. Two culture media were compared, control medium (DMEM) with and without supplementation of l-proline (final concentration 60 mug/ml). In both culture models, after an initial decrease, total GST activities increased significantly up to values higher than those observed for freshly isolated cells. The Mu class GST activities were maintained constant for 7 days and increased thereafter. l-Proline supplementation of the culture medium prevented the initial decline in total and Mu class GST activities in both culture configurations but did not seem to be of crucial importance in the maintenance of GST activities in both culture models.
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PMID:Collagen gel sandwich and immobilization cultures of rat hepatocytes: Problems encountered in expressing glutathione S-transferase activities. 2065 79

Liver parenchymal cells (hepatocytes) of human organ donors were isolated using a two-step collagenase perfusion technique. The average viability of the freshly isolated liver parenchymal cells, as judged by trypan blue exclusion, was 82% (SD = 7%; n = 6). The inter-individual differences in the determined enzyme activities were less than a factor of 7.5, despite the different sexes and ages of the donors. Freshly isolated parenchymal cells (PC) were cryopreserved using a computer-controlled freezing protocol. After thawing, cryopreserved cells had a mean viability of 57% (SD = 18%; n = 6). The activities of xenobiotic metabolizing enzymes in freshly isolated and cryopreserved cells were compared using PC from two donors. The enzyme activities of phenol sulfotransferase, 1-naphthol UDP-glucuronosyltransferase and microsomal epoxide hydrolase were well maintained after thawing (87-117% of activities in freshly isolated cells), whereas the activities of glutathione S-transferase, monitored with the broad spectrum substrate 1-chloro-2,4-dinitrobenzene, and the major broad spectrum cytosolic epoxide hydrolase were moderately but markedly reduced after cryopreservation (34-64% and 45-89% of levels in fresh cells, respectively). The decrease of both activities was dependent on the viability after thawing. When cryopreserved cells were purified by a Percoll centrifugation after thawing, the viability was increased from 62 to 92% for cells from one of the donors and from 88 to 98% for PC for the other donor. Subsequently the activity of glutathione S-transferase in Percoll-purified PC from the two donors was increased to 71 and 96% of levels in freshly isolated cells. It is concluded that the use of cryopreserved liver parenchymal cells of humans and other species represents a valuable tool in predicting which animal species best represents humans in hepatic metabolism and therefore should be the preferred species for investigations of metabolism and metabolism-dependent toxicities.
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PMID:Xenobiotic metabolizing enzyme activities in isolated and cryopreserved human liver parenchymal cells. 2069 84