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)

In an attempt to clarify the Kupffer cell function in alcoholism, chronic ethanol-fed rats were investigated. The clearance of latex particles in the rat was analysed to estimate the function of the reticuloendothelial system in the liver, and the phagocytic function of Kupffer cells was measured by counting particles in the cell after isolation of non-parenchymal cells by collagenase digestion of the liver following an injection of latex particles and subsequently by staining of endogenous peroxidase activities. In addition, the number of Kupffer cells and their phagocytic function were examined histologically in fresh frozen sections of liver after an injection of particles. Serum ethanol concentration in the ethanol-fed rats was 10-60 mumol/l. The clearance of latex particles was markedly reduced in the ethanol-fed rats as compared with the paired controls (P less than 0.01). Markedly decreased-phagocytic function was found in 20% of Kupffer cells in the chronic ethanol-fed rats. The number of Kupffer cells in the ethanol-fed rats was increased as compared with the paired control rats. Chemotaxis analysis revealed that hepatocytes when incubated with ethanol, produced chemotactic factor for Kupffer cells and polymorphonuclear cells. These abnormal Kupffer cell functions may contribute to the pathogenesis of alcoholic liver disease.
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PMID:Kupffer cell function in chronic ethanol-fed rats. 269 94

The participation of histamine in ethanol-induced inflammation has been estimated in rats. Administration of ethanol caused an increase in the total number of blood leukocytes and changed the composition of the leukocyte population. The histamine receptor antagonists mepyramine and cimetidine did not affect the changes in cellular composition. Pretreatment with the anti-allergic drug Tritoqualine had no effect on the total number of leukocytes and PMN-leukocytes. PMN-leukocytes from ethanol treated rats had a greater capacity to activate latent collagenase. This ability was partially inhibited by the histamine receptor antagonists mepyramine and cimetidine, particularly in combination. Pretreatment with Tritoqualine apparently protected the latent collagenase against ethanol activation. Thus we conclude that histamine is possibly implicated in the process of generating activity for latent collagenase.
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PMID:Is histamine involved in ethanol-induced inflammation? 283 66

To facilitate investigations on very small fat cell (VSFC) populations in adipose tissue, an alternate method of preparing fat tissue samples was explored. The osmium tetroxide-8M urea method, modified by addition of a 95% ethanol step in tissue processing, centrifugation between steps, and final resuspension in 55% glycerol in 0.01% Triton-saline, was compared with the collagenase method for determination of VSFC populations in Fischer 344 epididymal and Sprague-Dawley retroperitoneal adipose depots. For each method and in both depots, the average histogram of 300 adipocyte diameters, measured by microscopy, was bimodal with the nadir between 30 and 40 micron diameter. The average histogram of fat cells less than 35 micron in diameter showed a separate population of VSFC existed in each depot. The modified osmium-urea method gave better results and was easier to perform than the collagenase method. It has confirmed our earlier results and raises anew questions concerning a role for the natural existence of a VSFC population in the adipose depot.
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PMID:Very small fat cell populations determined by a modified osmium tetroxide-urea method. 299 Feb 29

A new type of microcarrier was described using bead emulsion-polymerization techniques. An aqueous solution of gelatin and glutaraldehyde was dispersed in a hydrophobic phase of mineral oil, using Triton X-114 as an emulsifier, and polymerization was initiated. The resultant spherical beads, composed entirely of gelatin, showed excellent mechanical stability to ethanol drying, sterilization, and long-term use in microcarrier spinner cultures. The solid gelatin microcarriers supported the growth of L-929 fibroblast, swine aorta endothelial, human umbilical endothelial, and HeLa-S3 cultures with no adverse effects on cell morphology or growth. The beads were transparent in growth medium and attached cells were clearly visualized without staining. The beads were also compatible with techniques for scanning electron microscopy. Collagenase could be used to entirely digest the gelatin beads, leaving the cells free from microcarriers and suspended in solution while retaining 98% cell viability. The results further showed that after collagenase treatment the cells would populate fresh gelatin microcarriers and grow to confluence. Cell attachment kinetics revealed that the endothelial cells attached to the gelatin beads at the same rate as to tissue culture plates, whereas the fibroblast cells attached to the beads more slowly. However, once the fibroblast cells were attached to the gelatin microcarriers they spread and grew normally.
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PMID:Pure gelatin microcarriers: synthesis and use in cell attachment and growth of fibroblast and endothelial cells. 299 23

Sake, a rice wine, induced hepatic collagen accumulation in rats. This was noted after 16 weeks of a liquid diet containing 35% ethanol by caloric content. However, under similar experimental conditions, whiskey and ethanol did not produce any changes. Hepatic collagenase activities in sake-fed rats were slightly, but significantly, higher than in the whiskey group. The central and pericellular liver fibrosis in sake-fed rats was caused possibly by either accelerated collagen synthesis or maturation, exceeding the increased collagen degradation. Mechanisms of enhanced fibrogenesis in sake-fed rats were discussed.
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PMID:Accumulation of hepatic collagen following long-term administration of sake to rats. 300 74

The effect of phenobarbital pretreatment on acinar distribution of microsomal drug metabolizing enzymes was investigated by analysis of periportal (pp) and perivenous (pv) enriched rat hepatocytes isolated by collagenase gradient perfusion. In untreated animals the activities of cytochrome P-450, NADPH-cytochrome c reductase and microsomal ethanol oxidation were significantly higher in pv cells. Phenobarbital produced a 45% increase of the yielded microsomes related to the hepatocytic protein but did not change their relative distribution. The content of reduced glutathione (GSH) was lower in hepatocytes from the pv area. The GSH content was more than 20% increased after phenobarbital treatment in both subclasses of cells, but the distribution pattern remained unchanged. The higher activity of drug metabolizing enzymes in the pv area of untreated animals may account for the higher cytotoxicity of numerous drugs to the perivenous hepatocytes. A 3-day treatment with phenobarbital equalized the pp-pv difference by producing more induction of the periportal cytochrome P-450-mediated drug and ethanol oxidation capacities in microsomes derived from periportally enriched hepatocytes.
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PMID:The distribution of cytochrome P-450-mediated drug oxidation and glutathione in periportal and perivenous rat hepatocytes after phenobarbital treatment. 308 68

The aim of this work was to determine whether treatments of rats with estradiol (E) in conditions known to decrease the proliferation rate, the mitotic index and the thymidine incorporation into the DNA of the MtTF4 tumor act at a specific point in the cell cycle. Two weeks after grafting a piece of tumor under the kidney capsule, adult male Fischer rats were treated or not treated with E. Tumors were collected between 12 h and 11 days later. Cells were dispersed by collagenase-DNAse treatment and fixed with ethanol. DNA content, cell size, cell granularity and protein content were analyzed, alone or in combination with a flow cytometer. E treatments did not apparently modify the distribution of cells according to their DNA content whereas they did increase dramatically cell size, cell granularity and cell protein content. Simultaneous analysis of DNA content and light scattering or protein content allowed us to demonstrate that there was an increase of a population of large granular and protein-rich cells regardless of the phase of the division cycle considered. These effects are time-dependent, dose-dependent and hormone-specific. This work shows both the interest of flow cytometry to describe the consequences of E treatment at any phase of the cycle of cells dispersed from a solid tumor and the limits of this method in the conditions used to specify the E target points: at the present time, it cannot be decided whether E acts at one or several points of the cell cycle for inhibiting tumor growth.
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PMID:Flow cytometry analysis of cells dispersed from the MtTF4 tumor whose growth is inhibited by estradiol treatment. 310 Mar 60

Periportal and perivenous hepatocytes were isolated by the digitonin-collagenase perfusion technique. The activity of the cytosolic glutathione S-transferase was higher in perivenous cells, but the cytosolic glutathione reductase and the microsomal glutathione S-transferase activities were evenly distributed. In contrast, both the Se-dependent and the microsomal Se-independent glutathione peroxidase activity and the glucose-6-phosphate dehydrogenase activity was much lower in perivenous hepatocytes, suggesting that these cells have a lowered detoxification capacity, which may contribute to their greater susceptibility to damage by xenobiotics. The mechanism of the ethanol-induced GSH depletion in vivo was studied by incubating conventionally isolated hepatocytes. In the absence of glutathione precursors, ethanol (80 mM) did not influence the GSH content, despite accumulation of acetaldehyde (10-100 MicroM). L-Methionine or L-cysteine stimulated GSH replenishment to in vivo rates. Ethanol oxidation resulted in acetaldehyde accumulation, but did not inhibit GSH replenishment from L-methionine and even stimulated that from L-cysteine. This seems to exclude conjugation of GSH with acetaldehyde as a mechanism by which ethanol suppresses GSH levels in vivo.
Alcohol Alcohol Suppl 1987
PMID:Glutathione metabolism in isolated rat hepatocytes: acinar heterogeneity of detoxifying enzymes and effects of ethanol. 342 86

Measurement of chemically induced DNA repair as unscheduled DNA synthesis (UDS) in rat hepatocytes following in vivo exposure has been shown to be a useful indicator of the genotoxicity of chemicals in rat liver. We have examined some of the parameters of this assay in an attempt to increase its sensitivity and reduce cytoplasmic backgrounds. Fischer-344 rats were treated with a low dose of a known positive chemical, water, or corn oil. Livers were perfused with a collagenase solution and isolated hepatocytes were incubated with [3H]thymidine (3H-TdR) followed by overnight incubation in unlabeled TdR, then cell fixation and washing. UDS was measured by quantitative autoradiographic grain-counting as net grains/nucleus (NG). Incubation in 3H-TdR ranging in age from 1 week to more than 12 months gave highly variable background (BKG) and NG counts and a slight overall decrease in NG when the 3H-TdR used was more than 4 months old. Control BKG was 3 times higher after 19 h than after 4 h of incubation in 3H-TdR, with little change in NG. Incubation in unlabeled TdR also reduced BKG significantly. Reduction of autoradiogram exposure from two to one week cut BKG in half without significantly reducing NG. A half-hour wash in fixative (1:3 acetic acid:ethanol) followed by two water washes was as effective in reducing BKG as three 10-min washes in fixative followed by 6 water washes, and resulted in better overall cell attachment. An examination of the distribution of historical control data shows that vehicle control animals never exceed zero NG. This suggests that any NG response greater than zero should be viewed as a possible positive response.
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PMID:Factors that affect the sensitivity of the in vivo-in vitro hepatocyte DNA repair assay in the male rat. 367 Mar 37

Acetaldehyde, the first metabolite of ethanol, mediates many of the biological effects of ethanol. We have previously shown that acetaldehyde, but not ethanol, stimulates collagen production in cultured human fibroblasts (Holt, K., Bennett, M., and Chojkier, M. (1984) Hepatology 4, 843-848). Here, we examined the effects of acetaldehyde on collagen gene expression. Confluent human fetal fibroblasts were incubated for up to 4 h in the presence of ascorbate (0.2 mM) alone or with the addition of either ethanol (12 mM) or acetaldehyde (200 microM). Acetaldehyde induced the production of collagen (up to 2.5-fold) and had a small inhibitory effect on procollagen secretion (-20%). The steady-state levels of mRNAs were measured by hybridizing total cellular RNA to specific cDNA probes at high stringency. Acetaldehyde increased the steady-state level of collagen alpha 1(I) and collagen alpha 2(I) mRNAs about 3-fold and had small effects on beta-actin mRNA (+50%) and collagenase mRNA (-50%). Northern blots revealed that the RNAs were intact and that acetaldehyde preferentially increased the abundance of the longer of the two collagen alpha 1(I) transcripts. Acetaldehyde increased both collagen alpha 1(I) and collagen alpha 1(III) transcriptional activity by 2.5-fold and had small effects on beta-actin and collagenase gene transcription. The increase in both collagen production and collagen mRNA levels induced by acetaldehyde was blocked by methylene blue, a scavenger of reducing equivalents. These data indicate that reducing equivalents, which enhance the formation and stability of acetaldehyde-protein adducts, may be required for acetaldehyde-stimulated collagen production. Thus, this study suggests that acetaldehyde increases collagen production by increasing collagen gene transcription in cultured human fibroblasts.
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PMID:Acetaldehyde increases collagen gene transcription in cultured human fibroblasts. 369 68


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