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)

The urinary bladder of Bufo marinus excretes H+ and this excretion is increased by metabolic acidosis (MA), insulin (IN), prostaglandin E2 (PGE2), increases CO2, and aldosterone. The purpose of this experiment was to determine whether MA, IN, PGE2, CO2, and aldosterone stimulate inositol phosphate's (IP) formation in isolated cells of toad urinary bladder. Cells were prepared by treating bladder sacs with collagenase. Cells were obtained from 10 toads in MA and 10 normal toads, suspended in 2 ml of Ringer's solution containing LiCl (10 mM), myo-inositol (5 mM), and [3H]myo-inositol (10 microCi), and then incubated for 2 hr at 25 degrees C. Cells were homogenized and the IP fractions quantitated by column chromatography and liquid scintillation counting. The results were expressed as dpm (mu MPO4)-1 (hr)-1. The IP in MA cells was 44,202 +/- 4,646 and in normal toad cells it was 31,637 +/- 3,613 (P < 0.05). In a separate experiment, cells from 10 paired hemibladders were isolated from normal toads. The cells were treated exactly as above except there were no LiCl in the bath. LiCl was added to all baths after 2 hr and the experimental cells were challenged with IN, PGE2, increases CO2, and aldosterone for 20 min. The IP were quantitated as above. IN treatment stimulated inositol bisphosphate and inositol triphosphate (P < 0.01). PGE2 and increases CO2 also stimulated inositol triphosphate (P < 0.05). Aldosterone did not alter formation of any of the IP fractions. We conclude that MA, IN, PGE2, and increases CO2 stimulate IP formation in cells of toad urinary bladder and inositol triphosphate may be an important second messenger in mediating the response of MA, IN, PGE2, and increases CO2.
...
PMID:Stimulation of phosphoinositides by agents that stimulate proton secretion in toad urinary bladder. 841 76

The release of secretin was studied in secretin cell-enriched preparations isolated from canine duodenal mucosa. The crude enterocytes were isolated by treating the duodenal mucosa sequentially with collagenase and ethylenediaminetetraacetic acid. Secretin cell-enriched fraction was prepared by centrifugation of the crude enterocytes in a counterflow elutriation rotor to obtain a final preparation containing 3.2 +/- 0.3 pmol/10(6) cell of immunoreactive secretin, which was 13-fold greater than the crude cell preparation (N = 5). The cells were incubated in Hanks' balanced salt solution for 20 min at 37 degrees C under 95% O2/5% CO2 before adding various agents and further incubated for various periods of time. The amounts of secretin released into the medium and retained by the cells were then determined by a specific radioimmunoassay. The release of immunoreactive secretin was increased dose-dependently over the control by dibutyryl cyclic-3',5'-adenosine monophosphate, forskolin, 4 beta-12-O-tetradecanoylphorbol-13-acetate, the synthetic serine protease inhibitor, camostat, and the calcium ionophore, A23187. The effects of forskolin, the phorbol ester, and A23187 were time-dependent and not observed at 4 degrees C. The release of immunoreactive secretin was also stimulated by KCl in high concentration and by sodium oleate. The effect of A23187 was abolished in a Ca(2+)-free medium, while those of dibutyryl cyclic-3',5'-adenosine monophosphate and forskolin were potentiated by 3-isobutyl-1-methylxanthine, which did not have a significant effect when added alone. These results indicate that the release of secretin is regulated by both Ca(2+)- and cyclic-3',5'-adenosine monophosphate-dependent mechanisms.2+ release.
...
PMID:Characterization of secretin release in secretin cell-enriched preparation isolated from canine duodenal mucosa. 842 47

The hypothesis that general anesthetics protect energy reserves by decreasing energy demand is widely accepted but poorly substantiated. Isoflurane at clinical doses preserved adenosine triphosphate (ATP) levels in anoxic isolated hepatocytes. Specific inhibitors were used to block mitochondrial and/or glycolytic ATP formation to ascertain whether pathways of energy supply or demand, or both, were involved in ATP preservation by isoflurane. Hepatocytes were isolated from fed adult male rats after perfusing livers with Krebs buffer containing collagenase. Cells were incubated in Krebs buffer for 0-30 min at 25 degrees C under N2/CO2 (95%/5%) +/- isoflurane 0.63 mM in liquid phase. Oligomycin, iodoacetate, or fasting were used to block mitochondrial and glycolytic ATP formation. Under anoxia alone, ATP levels declined more slowly in the presence than in the absence of isoflurane, confirming the ATP-protective effect of isoflurane reported previously. With oligomycin plus iodoacetate blocking all ATP formation, ATP decline (representing pure ATP consumption) was not slowed by isoflurane. Isoflurane's protective effect recurred when glycolytic ATP supply was restored by incubating with oligomycin only. The protective effect was accompanied by increased lactate accumulation, and both effects-ATP preservation and lactate formation-were similarly dependent on isoflurane concentration. We conclude that the protective effect of isoflurane on energy status in anoxic isolated hepatocytes was not associated with reduced ATP demand but with enhanced ATP supply via stimulation of glycolysis.
...
PMID:Isoflurane preserves adenosine triphosphate levels in anoxic isolated rat hepatocytes by stimulating glycolytic adenosine triphosphate formation. 863 2

This study employed immunocytochemistry and toluidine blue counterstaining to compare different procedures utilized in primary myoblast cultures, from which an optimal culture model for normal myoblasts could be derived. The growth characteristics of normal and dystrophic myoblasts were also investigated by means of this model. Results indicate that the requirements for an ideal myoblast culture should include a combined enzyme of 0.25% trypsin and 0.2% collagenase (type IV) (1:1), a preplating time of approximately 15-20 minutes, and a seeding density of 1 x 10(5) cells/ml. Furthermore, the mouse samples should be newborn mice. A better proliferative capacity of myoblasts was noted in an incubator with 10% CO2 coupled with Dulbecco's MEM plus 15% fetal calf serum. With regard to the growth characteristics of normal and dystrophic myoblasts, the doubling time of normal myoblasts was shorter than that of dystrophic myoblasts. In terms of the fusion percentage of myoblasts, dystrophic myoblasts tended to fuse earlier than normal ones, especially after 5 days in culture. The findings of this study are valuable in understanding the myogenesis of myoblasts under different culture conditions. The establishment of requirements for good growth of myoblast cultures will facilitate myoblast transfer therapy. Finally, the growth characteristics of normal and dystrophic myoblasts as well as variances in the proliferation and differentiation of these two types of cells are clarified.
...
PMID:Growth characteristics of normal and dystrophic myoblasts in primary myoblast cultures. 893 42

We have shown that cutaneous burn injury impairs cardiac contractile performance; however, the mechanisms remain unclear. In this study, New Zealand White rabbits were anesthetized with isoflurane, given a full-thickness scald burn over 30% of total body surface area, and resuscitated with lactated Ringer solution (4 ml.kg-1.%burn-1 for 24 h); rabbits handled in an identical fashion were given a sham burn. Serum obtained from burned and control (sham-burned) rabbits was aliquoted and frozen at -70 degrees C until assay. Polymorphonuclear neutrophils (PMN) were isolated 24 h postburn from both sham and burned rabbits to yield preparations with > 95% PMN with > 95% viability. Cardiac myocytes were isolated by retrograde perfusion of hearts with Ca(2+)-free collagenase-Tyrode buffer, suspended in Krebs-Henseleit buffer containing 10% fetal bovine serum and 1.8 mM Ca2+, and incubated (1 x 10(5) cells/well) in a CO2 incubator under several experimental conditions, including buffer alone, buffer plus 10% burn serum, buffer plus 10% sham serum, or buffer plus either burn or sham PMN (25 x 10(5) cells/well). Myocyte viability (%) and creatine kinase (CK; units.ml-1.10(5) cells-1) were unchanged after incubation with sham plasma or sham PMN. Incubation of sham myocytes with burn plasma caused viability to fall (from 79 +/- 3 to 54 +/- 4%, P < 0.002), whereas CK rose (from 1,639 +/- 115 to 2,803 +/- 132 units.ml-1.10(5) cells-1, P < 0.01). Similarly, incubation of sham myocytes with burn PMN reduced viability (from 83 +/- 2 to 50 +/- 3%, P < 0.01), whereas CK remained unchanged (1,880 +/- 168 units.ml-1.10(5) cells-1). Our data indicate that circulating myocardial depressant factors after burn injury contribute to cardiac myocyte injury.
...
PMID:Cellular basis for burn-mediated cardiac dysfunction in adult rabbits. 899 23

Paraquat (PQ) induces lung, liver and kidney damage. Since PQ mainly is eliminated by the kidney, the kidney damage is of particular importance to the outcome of PQ poisoning. The exact toxic mechanism of PQ is still unclear but it is assumed to involve redox cycling and formation of reactive oxygen species. In this study, further investigations on the toxic mechanism and metabolic effects of PQ were performed using isolated renal proximal tubules from rabbits. Proximal tubules were isolated using a combined iron perfusion and collagenase method. Suspended tubules were incubated for varying periods and concentrations of PQ at 25 or 37 degrees C in Krebs-Ringer phosphate buffer or HCO3-/CO2 buffer. The cytotoxic effect of PQ was evaluated by (1) markers of oxidative stress: status of glutathione (GSH/GSSG) and formation of malondialdehyde (MDA); and (2) markers of tubular metabolism: oxygen consumption (QO2), transport of 14C-p-aminohippuric acid (PAH) and 14C-tetraethylammonium (TEA). Using 0.5 and 5 mM PQ, the GSH/GSSG ratio decreased whereas formation of MDA increased indicating oxidative stress. PQ reduced the accumulation of PAH and TEA, the basal QO2 and the ouabain sensitive QO2 indicating inhibition of the Na/K-ATPase. Nystatin-stimulated QO2 was reduced by PQ, excluding inhibition of Na+ entry as a possible cytotoxic mechanism and suggesting mitochondrial injury. This was confirmed by measuring FCCP-uncoupled QO2. Thus high concentrations of PQ appear to disrupt mitochondrial electron chain transfer resulting in reduction of metabolic functions.
...
PMID:The cytotoxic effect of paraquat to isolated renal proximal tubular segments from rabbits. 927 8

Tumor necrosis factor (TNF) is involved in the pathogenesis of acute sepsis-induced organ injury and has been implicated as a mediator of metabolic alterations observed during sepsis. Pancreatic islet cell function may be significantly compromised during sepsis or endotoxemia, and sepsis also increases plasma levels of epinephrine, a modifier of islet insulin secretion. We proposed that islets exposed to bacterial lipopolysaccharide (LPS) produce TNF and that epinephrine attenuates islet secretory activity. We monitored the effects of LPS and epinephrine on TNF and insulin activity of isolated Wistar-Furth rat islets (pancreas digested with collagenase, islets isolated using Ficoll gradients; n = 4 islet populations, each with 632 +/- 11 islets/2.5 ml culture medium). Islets were incubated (37 degrees C, 5% CO2) 3 days. LPS (Escherichia coli, 1 microgram/ml) and epinephrine (14 micrograms/ml) were added to the islets, and incubations were continued for 1-4 h. Glucose (Beckman Glucose Analyzer), insulin (radioimmunoassay), and TNF (L929 cytotoxicity assay) were measured in the islet medium samples at 1- to 4-h time points. In the conditioned medium, glucose decreased (P < 0.05), insulin increased (P < 0.05), and exposure to LPS did not alter these levels [P = not significant (NS)] but did increase TNF activity by 400% (P < 0.05). Epinephrine reduced insulin by 38-43% (P < 0.05) and TNF by 20-25% (P < 0.05) but had no effect on glucose levels (P = NS). We conclude that insulin is secreted from isolated islets and that exposure to LPS acutely increases islet-derived TNF activity, whereas epinephrine modifies TNF and insulin secretion of rat pancreatic islets.
...
PMID:Tumor necrosis factor activity of pancreatic islets. 927 98

The present report concerns a patient who had undergone nearly total pancreatectomy (95%) with pancreatic islet autotransplantation for intractable pain caused by obstructive chronic pancreatitis. Islets were prepared by a modified collagenase digestion and were cultured in vitro in Eagel's medium in 5% CO2 in air at 37 degrees C for 5 days. The resultant preparation, containing about 150,000 islets, was injected into the recipient's liver via the umbilical vein. No complication occurred from the pancreatectomy or transplant. Postoperatively, the patient had complete relief of the abdominal pain, and the insulin-independent condition remained with normal fasting blood glucose, and hemoglobin A1c for 11 months. Subsequently the fasting hyperglycemia was evident, and the patient began oral antidiabetic medication, but 2 year after transplantation the insulin-dependent condition demanded exogenous insulin (24 U). At present the fasting serum C-peptide level is 0.6 ng/ml and the HbA1c of 5.8% confirms the normoglycemic condition at the same insulin dose. Islet auto-transplantation should be considered as an adjunct procedure to prevent or ameliorate diabetes after total or nearly total pancreatic resection.
...
PMID:[Management of diabetes induced by nearly total (95%) pancreatectomy with autologous transplantation of Langerhans cells]. 928 Aug 85

Both cold and warm ischemia occur during liver transplantation. Hypothermia and Wisconsin solution preserve adenine nucleotide energy status, which is crucial to hepatic function and viability. The volatile anesthetic isoflurane has been shown to preserve energy status in anoxic isolated hepatocytes in warm Krebs solution. The present study examined isoflurane effects on energy status during incubation also in Wisconsin or Krebs-plus-adenosine solution at 37 degrees or 4 degrees. Hepatocytes were isolated from rat liver after perfusion with Krebs + collagenase. In 25-mL flasks, 12.5 million cells in 2.5 mL of Krebs, Krebs plus 5 mmol/L adenosine, or Wisconsin solution were incubated under an atmosphere of O2/CO2 or N2/CO2 (19:1) +/- isoflurane (3 volumes% = 2ED50), for 30 minutes at 37 degrees C or 4 degrees C. Adenine nucleotides were measured by high-performance liquid chromatography (HPLC), lactate enzymatically. During warm (37 degrees) anoxia, Wisconsin solution preserved energy status; Krebs plus adenosine did not. Isoflurane further protected energy status in all three solutions. Hypothermia (4 degrees) alone greatly decreased anoxic loss of energy status in all solutions. In Wisconsin solution only, energy status tended to be higher in anoxic than in oxygenated cells and was further enhanced by isoflurane, with corresponding increases in lactate. During 30 minutes of either warm or cold anoxia, isoflurane and Wisconsin solution each helped preserve adenine nucleotide energy status in isolated hepatocytes, at least in part through enhanced glycolysis.
...
PMID:Energy status in anoxic rat hepatocytes: effects of isoflurane, solution composition, and hypothermia. 934 69

The present study was undertaken to provide further information on lipogenesis in isolated adipocytes from the subcutaneous adipose tissue of fattening steers. The main aims were to compare different incubation media and to clarify the effects of fetal bovine serum (FBS) on lipogenesis and substrate oxidation rate in the adipocytes. The isolated adipocytes were prepared by the collagenase digestion technique. The changes in cellularity, the incorporation rates of acetate or glucose into lipid molecules, and the oxidation rates to CO2 both in fresh and preincubated adipocytes were measured in different media. It was shown that FBS increased significantly both lipogenesis and the oxidation rates of glucose or acetate in the fresh adipocytes but insulin did not. In isolated adipocytes preincubated for 24 and 48 h, the cellularity, the incorporation rate of glucose into lipid molecules, and the oxidation rates of glucose or acetate to CO2 were not different to those in fresh adipocytes, but the incorporation rate of acetate into lipid molecules was significantly lower.
...
PMID:Effect of different experimental conditions on lipogenesis and substrate oxidation in isolated adipocytes from fattening Holstein steers. 943 52


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

---