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)

We have shown previously that ethanol-induced defects in receptor-mediated endocytosis of asialoorosomucoid occurred as early as 1 wk after ethanol feeding. This study was undertaken as an initial attempt to establish a possible role of defective receptor-mediated endocytosis in liver injury by investigating whether differences exist in the effects of ethanol on receptor-mediated endocytosis in hepatocytes isolated from different regions of the liver. Perivenule cells, present in the distal half of the liver, are thought to be more susceptible to ethanol-induced liver injury than are the periportal cells located in the proximal half of the liver acini. For these studies, we fed male Sprague-Dawley rats for 7 days with liquid diets containing either ethanol (36% of calories) or isocaloric carbohydrate. Perivenule and periportal hepatocytes were then isolated using a digitonin-collagenase perfusion method. In control animals, cells isolated from the perivenule region bound significantly more ligand than did cells from the periportal region. Amounts of ligand internalized and degraded were also greater in perivenule than in periportal cells in these animals. After ethanol feeding, cells isolated from both the perivenule and periportal regions bound significantly less ligand than their respective controls. This impairment in surface and total binding was more pronounced in perivenule than in periportal cells. Internalization and degradation of the ligand were also more adversely affected in the centrilobular region as shown by decreases of greater than 60% in perivenule cells and by only 20% to 30% in periportal cells of ethanol-fed animals compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Zonal differences in ethanol-induced impairments in receptor-mediated endocytosis of asialoglycoproteins in isolated rat hepatocytes. 199 36

During infection or endotoxemia, the immune system is activated and its energy needs increase. Alcohol (ETOH) intoxication on the other hand suppresses the immune system and increases susceptibility to infection. Since the liver is the primary site both for metabolism of ETOH and detoxification of bacterial lipopolysaccharides (LPS), this investigation was directed at studying the effect of acute ETOH intoxication on the LPS-induced enhancement of in vivo glucose utilization in different types of hepatic cells. Rats were given an intravenous (IV) injection of ETOH followed by a constant infusion for 7 hr to maintain blood alcohol levels at about 175 mg/dl. E. coli LPS was administered IV at 4 hr and in vivo glucose utilization by the different types of liver cells was estimated 3 hr later using the 14C-2-deoxyglucose technique. Hepatocytes (HP), Kupffer (KC), and endothelial cells (EC), as well as the sequestered polymorphonuclear leukocytes (PMN), were separated from the liver by collagenase-pronase digestion followed by centrifugal elutriation and Ficoll-Hypaque density gradient centrifugation. The number of PMN in the liver was increased several-fold 3 hr after LPS administration. The presence of ETOH did not inhibit the LPS-induced neutrophil migration into the liver. ETOH depressed the LPS-induced increase in glucose uptake in both EC and KC by 50 to 80%, respectively. It also reduced the LPS-induced increase of plasma tumor necrosis factor activity by 80%. ETOH alone did not produce any significant changes in the parameters studied.(ABSTRACT TRUNCATED AT 250 WORDS)
Alcohol Clin Exp Res 1991 Mar
PMID:Acute ethanol intoxication suppresses E. coli lipopolysaccharide enhanced glucose utilization by hepatic nonparenchymal cells. 205 1

The ethanol-inducible form of cytochrome P-450 (IIE1) is expressed and induced by ethanol, predominantly in the centrilobular region. Because this isoenzyme has a particularly high capacity to convert carbon tetrachloride and several other hepatotoxins into reactive intermediates, its role in producing damage was studied by comparing the effect of carbon tetrachloride exposure on hepatocytes isolated from either the periportal or the perivenous region by digitonin-collagenase perfusion. After exposure for 18 hr of primary culture to 600 mumol/L of carbon tetrachloride, periportal cells were only slightly damaged, as estimated from dye exclusion and lactate dehydrogenase leakage. In marked contrast, perivenous cells, which contained a several-fold higher amount of immunoreactive P-450 IIE1 apoprotein, were partly damaged after exposure to 60 to 150 mumol/L of carbon tetrachloride and severely damaged after 600 mumol/L. Similarly, lipid peroxidation after carbon tetrachloride was much more prominent in perivenous cells. The differences between perivenous and periportal cells in carbon tetrachloride-induced injury were larger when cells were isolated from chronically ethanol-treated rats. Isoniazid, an efficient inhibitor of P-450 IIE1, protected against damage by carbon tetrachloride more efficiently than the general P-450 inhibitor cimetidine. Our results suggest that the greater susceptibility of the perivenous hepatocytes to carbon tetrachloride-induced damage is associated with the high expression of P-450 IIE1 in these cells. This enzyme may also be involved in damage elicited by several other typical centrilobular hepatotoxins.
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PMID:Role of ethanol-inducible cytochrome P-450 IIE1 in carbon tetrachloride-induced damage to centrilobular hepatocytes from ethanol-treated rats. 222 5

Cryopreservation of human parathyroid tissue plays an important role in managing difficult parathyroid disease. It also can permit investigators to conduct experiments without dependence on the operating room schedule. Availability of cryopreservation has been limited by the perceived need for expensive, complex equipment. We adapted a simple method of freezing cell suspensions to freezing human parathyroid tissue. Vials containing human parathyroid in culture media, dimethylsulfoxide, and patient serum were placed in a plastic rack in a metal pan containing prechilled (4 degrees C) ethanol and placed in a -70 degrees C freezer. We compared viability (trypan blue dye exclusion by collagenase dispersed cells) of tissue frozen in this manner to that of tissue frozen in a programmable liquid nitrogen freezer at 1 degrees C per minute, a cooling rate recommended for human parathyroid tissue. The viability of 30 patients' samples cooled in liquid nitrogen (average length of storage 5 months) was 74% +/- 15% and that of 64 patients' samples cooled in ethanol (average length of storage 26 months) was 71% +/- 15%. Viability of 19 samples of fresh tissue was 79% +/- 10%. Neither method had a statistically significant correlation between length of storage and viability. Successful cryopreservation with simplified technology may expand the availability of parathyroid tissue to meet both clinical and investigative requirements.
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PMID:Characterization of a simplified method of cryopreserving human parathyroid tissue. 224 27

We tested the effect of ethanol and its metabolite, acetaldehyde, on bone formation as measured by [3H]proline incorporation into collagenase digestible protein (CDP) and noncollagen protein (NCP), and on DNA synthesis as measured by [3H]thymidine (TdR) incorporation in fetal rat calvaria. We also determined the effects of ethanol and acetaldehyde on prostaglandin E2 (PGE2) release from calvaria and on bone resorption as measured by 45Ca release from fetal rat long bones. Bones were cultured in multiwell plastic dishes (open system) or in stoppered Erlenmeyer flasks (closed system) for 24 to 96 h. In the open system, 1% ethanol (v/v; 172 mM) resulted in a 31% decrease in TdR incorporation at 24 h with no effect on CDP and NCP. At 0.1% (17.2 mM), ethanol increased TdR by 22%, CDP by 73% and NCP by 67% at 24 h, but these effects were not sustained at 96 h. At 24 h, 1% and 0.3% ethanol decreased PGE2 release by 88% and 75% respectively. This effect was sustained for 96 h only at the higher concentration. In the closed system, 0.1% ethanol increased TdR incorporation by 38% at 24 h. However, there was no effect on the labeling of CDP or NCP. Because its boiling point is 21 degrees C, acetaldehyde could only be tested in the closed system. Acetaldehyde markedly inhibited bone metabolism. At 24 h, 0.003% (0.54 mM) to 0.01% (1.79 mM) acetaldehyde caused a dose-related inhibition of TdR incorporation from 23 to 45%. At 0.01% and 0.03% acetaldehyde inhibited proline incorporation into CDP by 48% and 94% and NCP by 40% and 74% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of ethanol and acetaldehyde on collagen synthesis, prostaglandin release and resorption of fetal rat bone in organ culture. 233 31

Nutritional factors, especially the protein and fat content of the diet, may alter the likelihood of pancreatic injury after a number of insults, including chronic ethanol intake. This issue was studied experimentally by match-feeding rats liquid diets of varying protein content with and without ethanol. Protein synthesis and enzyme secretion were investigated, because these parameters are believed to increase the capacity for pancreatic autodigestion. Protein synthesis was assessed by determining the incorporation of tritiated phenylalanine into trichloroacetic acid precipitated protein 10 minutes after IP injection and then corrected for the size of the precursor pool. Enzyme secretion was studied using pancreatic acini, which were prepared using clostripain-poor collagenase. Chronic ethanol feeding stimulated protein synthesis and lipase secretion and content in rats receiving adequate amounts of protein. These stimulatory effects of ethanol were markedly attenuated in rats administered protein poor diets. Protein deficiency per se significantly decreased the weight, protein, and enzyme content of the rat pancreas as well as increased the percentage release of lipase from acini. Although extrapolation from animal studies may be tenuous, the present findings may explain the link between nutrition and the occurrence of alcoholic pancreatitis.
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PMID:Interactive effects of dietary protein and ethanol on rat pancreas. Protein synthesis and enzyme secretion. 198 46

A new technique for assessing vital and degenerative microfilariae (mf) in different skin layers of onchocerciasis patients is described. Vertical sections at least 5 mm deep were collected from the surgical nodulectomy wounds before and 2, 4 and 28 days after treatment with ivermectin and fixed in ethanol. Skin biopsies were punched horizontally with trephines and digested enzymatically with collagenase. In untreated biopsies 80% of the mf were located in the uppermost layer of 1 mm and only 1.2% were degenerated. After treatment with ivermectin the total number of mf was significantly reduced, and the distribution of living and remnant mf in the different skin layers had changed. The proportion of degenerated mf had increased markedly, but did not exceed 6% of the total pre-treatment mf level, i.e., the vast majority of the mf had actually disappeared from the skin. It is suggested that ivermectin reduces microfilarial motility slightly, and that mf are then attacked by adhering immunocompetent cells of the host and cleared by the lymphatic drainage.
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PMID:Effect of ivermectin on the vertical distribution of Onchocerca volvulus microfilariae in the skin. 238 96

The lens was removed from both eyes of adult newts (Notophthalmus viridescens), and the eyes were fixed in Karnovsky's fixative every 2 days 0-20 days after operation. Anterior half-eyes were prepared by standard procedures for scanning electron microscopy of the surface. Before fixation, the posterior iris surface was cleaned of adhering vitreous mechanically with forceps or by treatment with bovine testicular hyaluronidase or with hyaluronidase and collagenase. Some specimens were cryofractured in buffer or ethanol transverse to the mid-dorsal iris, and the fractured surface viewed with scanning electron microscopy (SEM). Cells with various combinations of ridges, blebs, filopodia, and lamellipodia were observed adhering to the posterior surface of the iris by 6 days after lentectomy. These cells, which exhibited the surface characteristics of macrophages, became more numerous in specimens fixed after longer intervals. Invasion of the iris epithelium was observed in a cryofractured specimen. After observations with SEM, selected specimens were embedded in plastic and sectioned for study with transmission electron microscopy (TEM). The cells on the iris surface had the cytological characteristics of macrophages, and other macrophages were located within the iris epithelium. In specimens fixed 16 or more days after lentectomy, a bulging lens vesicle was regenerating from the dorsal pupillary margin of the iris. Macrophages were absent or few on the surface of this developing lens but remained scattered over the adjoining iris. Roles that might be played by these macrophages during the transdifferentiation of iris epithelium into lens are discussed.
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PMID:Macrophage mobilization and morphology during lens regeneration from the iris epithelium in newts: studies with correlated scanning and transmission electron microscopy. 239 92

The application of flow cytometry (FCM) to solid human tumors has been hindered by the difficulty in producing high yield, viable, unaltered single cell suspensions. Carcinomas containing a high desmosomal content, such as well-differentiated squamous cell (SCC) cancers of the head and neck (H&N) region, are particularly difficult to prepare. The desire to employ FCM to study cellular DNA parameters of these tumors led to the use of a 3-methylcholanthrene induced murine SCC for the comparative testing of preparative techniques. Dissociation techniques, including mechanical, enucleation, chemical, single and combination enzymes methods, were comparatively tested. Of these, the combination enzyme treatment employing trypsin and collagenase produced the highest cell yields in the shortest time with the highest dye exclusion viability and the least expense. Several fixation systems including glutaraldehyde, paraformaldehyde, acetic acid, and ethanol were comparatively tested using percent of cell loss and quality of the DNA histograms produced as end points. Ethanol-water systems with added fetal calf serum provided minimal cell loss and high quality histograms which were stable for extended periods of time. A murine tumor, closely mimicking the histology of the human tumor of interest, may be used as a model for the determination of optimum techniques of solid tumor preparation for flow cytometric analysis.
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PMID:Solid tumor preparation for flow cytometry using a standard murine model. 244 98

Collagen metabolism in the pancreas was investigated in male Wistar strain rats after 7 weeks of ethanol feeding. Compared with control rats, the ethanol-fed rats had a normal hydroxyproline content in the pancreas. However, prolyl hydroxylase activity and collagenolytic cathepsin activity were increased, though collagenase activity did not change. Both prolyl hydroxylase activity and collagenolytic cathepsin activity were inversely correlated with amylase activities. These findings were also confirmed in ethanol-pyrazole treated rats. These results suggest that the ethanol-induced pancreatic injury, even at an early stage, accelerates the collagen metabolism in the pancreas.
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PMID:Effects of ethanol feeding on collagen synthesizing and degrading enzymes in rat pancreas. 244 47


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