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

---

Query: EC:3.4.24.3 (collagenase)
18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. A method for the preparation of isolated mammary gland cells of the rat is described. 2. The procedure involves disaggregation of the tissue in a collagenase-hyaluronidase mixture and subsequent purification of the heterogeneous population of cells by centrifugation in discontinuous Ficoll-400 gradients; the preparation takes 60 minutes. The yield of cells is approximately 14%. 3. The cells as prepared have high rates of metabolism and synthetic capacity and exhibit metabolic characteristics comparable to intact tissue. 4. Measurements of the content of metabolic intermediates show cells to have, and retain, outstandingly high levels of ATP and to have an energy charge close to 0.9. Levels of other intermediates approximate to those found in the intact tissue. The level of glycolytic intermediates below the triose phosphate stage indicate the highly aerobic state of the cells. 5. The pattern and scale of glucose utilization, measured using specifically labelled glucose incorporation into 14CO2 and 14C-labelled lipid production, approximates closely in isolated cells at 5 and 20 mM glucose and in tissue slices at 20 mM glucose concentration. Mammary gland slices incubated with 5 mM glucose have a considerably lower rate of metabolism. Isolated cells exhibit a higher proportionate rate of glucose utilization by way of the pentose phosphate pathway. 6. The isolated cells are hormone responsive. Insulin increases the oxidation of glucose by the pentose phosphate pathway and stimulates lipid synthesis. Addition of progesterone and cortisone in vitro (10 muM) leads to a marked and rapid decrease in the rate of glucose oxidation and conversion to lipid.
...
PMID:Regulation of mammary gland metabolism: pathways of glucose utilization, metabolite profile and hormone response of a modified mammary gland cell preparation. 67 49

Inapparent nodule-transformed cells were recovered from five late-pregnant, first-pregnancy BALB/cfC3H females 4 months of age and from five late-pregnant multiparous females 6 to 7 months of age. Mammary tissues were removed from each donor and dissociated by means of the enzyme collagenase (0.1%), hyaluronidase (0.1%), and pronase (1.25%). Aliquots of 100,000 viable cells in 0.01 ml of media were injected into the gland-free mammary fat pads of 3-week-old syngeneic host mice. Ten weeks after the injection the outgrowths were classified as ductal, nodule, tumor, or combinations of these types of outgrowths. The recovery of nodule outgrowths indicated the presence of nodule-transformed cells in the cell suspension that was injected. All donors yielded nodule outgrowths, and the percentage of outgrowths was significantly greater than was the percentage recovered from virgin BALB/cfC3H females of the same age groups. The latent period for the emergence of nodules and tumors was reduced from 8 to 9 months in virgin females to 4 months in parous females. The incidence of both nodules and tumors was greatly increased. The data suggest that parity significantly increases the numbers of nodule-transformed cells in donor tissue, decreases the time required for the emergence of nodules and tumors, and increases the number of overt nodules and tumors.
...
PMID:Effect of parity on recovery of inapparent nodule-transformed mammary gland cells in vivo. 69 53

Cell suspensions were generated from rat olfactory epithelium by digestion with collagenase and hyaluronidase followed by gentle mechanical disruption. These cell suspensions excluded nigrosin dye and synthesized RNA, protein and carnosine from radiolabeled precursors. Sustentacular cells, repiratory epithelial cells and olfactory neurons but not basal cells could be identified by phase-contrast microscopy. Sedimentation of these cell suspensions at unit gravity in discontinuous gradients of buffered bovine serum albumin resulted in partial separation of the various cell types as indicated by the distribution of several biochemical markers. Olfactory marker protein and carnosine synthetase activity were found in the upper gradient fractions, while carnosinase activity was present predominantly in the lower gradient fractions. Cellular localization of olfactory neuron marker protein and non-neuronal S-100 protein by immunoperoxidase staining of gradient-fractionated cells indicated that neuronal cells were only partially separated from non-neuronal cells by our fractionation techniques. Evaluation of gradient fractionated cells by histochemical staining for carbohydrates demonstrated that secretory Bowman's gland cells were quite efficiently separated from neurons. This study demonstrates the ease with which cell suspensions may be produced from the olfactory epithelium, and emphasizes the importance of utilizing both biochemical and histochemical approaches in studies of mixed populations of cells, particularly when the purity of the cell fractions is a consideration.
...
PMID:Cell suspensions from rat olfactory neuroepithelium: biochemical and histochemical characterization. 75 75

Thyroxine-binding globulin biosynthesis was demonstrated in hepatocytes isolated from normal adult Rhesus monkeys. Dispersed cells were obtained by in situ liver perfusion with collagenase, hyaluronidase and EDTA. Conditions for optimum cell survival and incorporation of radioactive leucine into newly synthesized proteins were defined. Protein synthesis, and specifically thyroxine-binding globulin synthesis, were shown to continue throughout the incubation period, while cell survival remained high (75% excluded trypan blue after 6h). Incubation medium, cytosol and a particulate fraction (extracted with digitonin) were analyzed for thyroxine-binding globulin. After extensive dialysis and purification by affinity chromatography, newly synthesized thyroxine-binding globulin was identified by specific double-antibody immunoprecipitation and by immunodiffusion and immunoelectrophoresis with autoradiography. Newly synthesized thyroxine-binding globulin was present after 4 h of incubation. After 6 h, the total synthesized had increased to 150% of the 4 h value, while the fraction present in the medium and increased to 300%, indicating probable thyroxine-binding globulin secretion
...
PMID:Thyroxine-binding globulin biosynthesis in isolated monkey hepatocytes. 81 66

1. A simple procedure for the isolation of morphologically intact, metabolically viable sheep liver parenchymal cells is described in detail. 2. The method is based on the initial treatment of fresh liver slices with collagenase and hyaluronidase. 3. The cell preparation was studied with respect to membrane permeability, potassium content, ATP/ADP ratio, adenylate content, and gluconeogenic capacity with respect to various substrates. 4. Data are present with respect to the distribution of phosphoenolpyruvate carboxykinase in isolated cells and whole sheep liver. 5. The results are compared, where possible, with data currently available from isolated perfused sheep liver and multi-catheterised animals.
...
PMID:Preparation and biochemical characterisation of isolated parenchymal cells from adult sheep liver. 83 5

Aortic tissues consisting of all three tunics were removed from normal adult rabbits and cultured in a semisynthetic gelosed medium supplemented by 10% serum obtained either from normal or hypercholesterolemic rabbits. Fibrillar cross-striated aggregates appeared with a high frequency (50%) in the extracellular space of explants cultured from four to eight days in medium supplemented by serum from hypercholesterolemic rabbits, but did not appear in explants cultured in serum from control animals (3%). The electron-dense segment was ruthenium red positive and digested by testicular hyaluronidase. The electron-lucent segment, composed of ruthenium red negative thin filaments, was not modified after hyaluronidase treatment but was strongly digested after collagenase treatment. It is believed that this material was fibrous long spacing collagen synthetized under culture conditions, as shown after tritiated proline incorporation.
...
PMID:Fibrous long spacing collagen in aortic explants of normal rabbit cultured in hypercholesterolemic serum. 91 68

Spontaneously contracting myocytes were isolated from ventricles of the adult rat heart. Hearts were perfused retrogradally via the aorta for 30 minutes at 37 degrees C with Ca2+-free phosphate-buffered saline containing collagenase and hyaluronidase. The venticles were divided into pieces and incubated 15 minutes with the enzymes. Dislodged cells were decanted, diluted with cold buffer and allowed to settle. The washed cells were then sedimented through 3% Ficoll. This procedure yielded approximately 50 mg of protein from 1 gm of heart. Viability measured by trypan-glue exclusion is 90-95%. Approximately 80% of the cells were beating. Scanning electron microscopic studies suggest that the isolated myocytes are morphologically intact. The cells oxidize glucose, pyruvate, citrate and palmitate to CO2 and synthesize protein and RNA. Uptake of glucose, 2-deoxyglucose, leucine and taurine was saturable. Glucose uptake was stimulated by insulin. The cells retained LDH and CPK as well as their capacity to oxidize substrates after 24 hours at 4 degrees C or 4 hours at 37 degrees C. After 24 hours at 4 degrees C the cells resume contracting when returned to room temperature. The procedure reported here for the isolation of spontaneously contracting, adult, rat heart myocytes provides cells with a high index of viability and greater yield than previously reported methods. The cells retain metabolic activity and withstand storage for longer periods than other described preparations.
...
PMID:Isolation and characterization of myocytes from the adult rat heart. 91 20

Release of peroxidase from secretory cells of rat lacrimal gland upon cholinergic stimulation was studied in vitro with single lobules and isolated cells (lacrimocytes). Isolated lobules, kept in Eagle's medium, remain structurally intact and reaction product of peroxidase is confined to cisternae of rough endoplasmic reticulum, elements of the Golgi apparatus, and all secretory granules. Morphologically, exocytosis occurs by membrane fusion and discharge of granule content. The highest rate of peroxidase released from lobules is observed at 10(-4) M carbamylcholine. The specific activity of peroxidase released into the medium is fourfold higher as compared to the lobules. Release of peroxidase is suppressed by atropine when added before or after the addition of carbamylcholine. At 4 degrees C, no peroxidase release occurs upon cholinergic stimulation. The exocytotic release of peroxidase is dependent on energy supply, as indicated by substantial inhibition (at 37 degrees C) under anoxic conditions or in the presence of dinitrophenol, KCN, or carboxyatractyloside. Furthermore, the process is sensitive to colchicine and vinblastine. Isolated lacrimocytes, consiting of 95% secretory acinar cells, are prepared by digestion with collagenase, hyaluronidase, and trypsin. They retain the characteristic polarity of secretory cells in situ, and localization of peroxidase is the same as in lobules. Since isolated lacrimocytes respond to cholinergic stimulation in the same way as lobules, the receptors are not damaged by the isolation procedure and appear to be associated directly with the exocrine cell. Oxygen uptake by isolated lacrimocytes is about 14 nmol O2 X min-1 X 10(-6) cells; it is about doubled by uncoupling with dinitrophenol. Oxygen uptake rises by 20-30% above the resting rate upon cholinergic stimulation. This additional uptake is suppressed by atropine or by added cholinesterase, indicating that continuous receptor occupancy may be required for the energy demand by exocytosis. On the basis of the specific activity of peroxidase in the medium, the energy demand resulting from cholinergic stimulation is estimated to be 0.08 mumol ATP (or energy-rich phosphate bonds) per microgram of protein released from the lacrimocytes.
...
PMID:Exocytosis in secretory cells of rat lacrimal gland. Peroxidase release from lobules and isolated cells upon cholinergic stimulation. 95 71

Rat hepatocytes were isolated by liver perfusion in the presence of collagenase and hyaluronidase and incubated in the absence or presence of oxygen. As a result of anoxia, there was a gradual increase in plasma membrane permeability, noted as an increase in succinate-stimulated oxygen uptake, a decrease in trypan blue exclusion frequency, a leakage of cytosolic lactate dehydrogenase activity and an increased proportion of swollen and disrupted cells. After anaerobic incubation for 30 minutes--but not for 60 minutes--there were signs of recovery from anoxic cell injury upon re-oxygenation. The changes in plasma membrane permeability properties in anoxia seemed to be preceded by a marked decrease in cellular ATP level; aerobic incubation of hepatocytes in the presence of an uncoupler of phosphorylation from respiration led to a similar decrease in cellular ATP concentration followed by similar disturbances in plasma membrane permeability properties. It is suggested that a distrubed plasma membrane function caused by a decreased energy level is of primary importance for the initiation of cell death in anoxia.
...
PMID:Isolated rat hepatocytes as an experimental tool in the study of cell injury. Effect of anoxia. 100 75

By perfusion of the isolated human liver with collagenase and hyaluronidase a mixed suspension of various cell types was obtained. Pure parenchymal cells were prepared by differential centrifugation, pure non-parenchymal cells by the use of pronase and subsequent isopycnic centrifugation on metrizamide gradients (50-300 g/l). About 90% of the parenchymal and non-parenchymal cells were viable as judged by trypan blue staining. Non-parenchymal cells were not capable fo gluconeogenesis but at high rates. Parenchymal cells retained their ability to form glucose and to accumulate glycogen from fructose greater than lactate/pyruvate greater than alanine. Studies on binding of 125I-labelled insulin by isolated parenchymal cells were performed at 30 degrees C. The binding data may fit with a minimum of two classes of binding sites: (a) high affinity--low capacity sties (Kd approximately 6.6 nmol/l, capacity approximately 16 000 insulin molecules per cell) and (b) low affinity-high capacity sites (Kd approsimately 0.37 mumol/l, capacity approximately 646 000 molecules per cell).
...
PMID:Preparation of parenchymal and non-parenchymal cells from adult human liver--morphological and biochemical characteristics. 100 13


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---