Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2-24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or alpha-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16-48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10(6) cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continued presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, alpha(1)-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.
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PMID:Proteases induce secretion of collagenase and plasminogen activator by fibroblasts. 20 72

Anaphylactic shock was induced in rabbits by injecting bovine serum albumin (BSA) as an antigen. Measurements of the enzyme activities in the fibrinolytic system confirmed that a rapid and strong increase of plasminogen activator (PA) was induced during anaphylaxis. The euglobulin fibrinolytic activity (EFA) as estimated by the plasminogen-rich fibrin plate method rose significantly, peaking at 15 min after the BSA injection (when the arterial pressure was minimum). However, EFA was not detected by the plasminogen-poor fibrin plate method. The tissue-type PA (t-PA) activity using the natural substrate plasminogen increased significantly with a peak at 15 min. The amidolytic activity also simultaneously increased significantly using the t-PA substrate, H-D-Ile-Pro-Arg-pNA. The plasminogen activator inhibitor (PAI) activity remained at baseline levels until 30 min, but rose fourfold at 90 min. The main plasma fibrinolytic enzyme which increased in anaphylaxis was proved by zymography to be t-PA with a molecular weight (MW) of 69,000.
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PMID:A rapid and strong increase of plasminogen activator induced by experimental anaphylaxis in rabbits. 129 30

The type of plasminogen activator (PA) secreted by bovine embryos was identified. Day 12-14 embryos were collected from estrus-synchronized, superovulated, and naturally mated crossbred beef cows. Embryos were left intact (E) or microdissected into component embryonic discs (ED) and trophoblastic vesicles (TV). Intact embryos, ED, and TV were pre-cultured for 2 days in Minimum Essential Medium Alpha (MEM alpha) with 10% heat-inactivated fetal calf serum, washed in serum-free MEM alpha, and cultured individually for 5 days in 50 microliters microdrops of MEM alpha with 15 mg/ml bovine serum albumin. At 24 hr intervals, E, ED, and TV were observed for tissue morphology and transferred to fresh microdrops, and medium was recovered and frozen at -20 degrees C. At the end of culture, blastocoelic fluid (BF) and embryonic tissues were recovered and frozen at -20 degrees C. Plasminogen activator concentrations in medium, tissues, and BF were determined by using a caseinolytic assay. Antibodies to urokinase-type PA (anti-uPA) and tissue-type PA (anti-tPA), and the urokinase inhibitor, amiloride (AMR), were used to identify the type of PA produced by bovine embryonic tissues. Intact embryos and TV released more PA (P less than 0.05) than ED, and tissues exhibiting expanded blastocoels released less PA (P less than 0.05) than tissues with collapsed blastocoels. Blastocoelic fluid from TV exhibited more PA (P less than 0.05) activity than from ED. Treatment with anti-uPA decreased PA activity (P less than 0.05) in pooled medium and tissues from E compared to treatment with nonspecific immunoglobulins and anti-tPA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Bovine embryos produce a urokinase-type plasminogen activator. 156 22

To elucidate the mechanism for thrombus formation in hypoalbuminemic and hyperlipidemic subjects, the experimental thrombus formation was analyzed in Nagase analbuminemic rats (NAR). The mutant rat reveals similar biochemical findings to those of NS, such as hyperlipidemia. When thrombus was induced in a small branch of the mesenteric artery by inserting a glass micropipette, thrombus formation was observed within 4 min in NAR and Sprague-Dawley rat (SDR). In SDR, the thrombus gradually grew up in size and detached from the inserted glass micropipette within 4 min after its formation. In contrast, the thrombus formed in NAR did not dissociate from the micropipette until 10-13 min after its formation. The maximum size of the thrombus formed in NAR was about 4 times larger than that in SDR. In the presence of fibrin, the plasma samples from NAR inhibited the activity of tissue-plasminogen activator (t-PA) 1.7 times more potently than did SDR plasma. Plasma gamma 2-plasmin inhibitor activity was significantly higher than that in SDR. Albumin significantly enhanced the t-PA-catalyzed activation of plasminogen, suggesting that the serum albumin might contribute, at least in part, to the plasma fibrinolytic activity. Thus, the higher thrombogenic potential in NAR than in SDR might be due to the reduced thrombolytic activity in NAR.
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PMID:Dynamic aspects of thrombus formation in mutant analbuminemic rats. 238 31

Using an immune complex-induced (IC) otitis media model in chinchillas sensitized with human serum albumin (HSA), we measured the levels of protease activity, protease inhibitors, and HSA in the middle ear fluid (MEF). The effect of a corticosteroid agent (triamcinolone) on the degree of IC otitis media also was studied. The levels of protease inhibitors alpha 1-antitrypsin and alpha 2-macroglobulin in the MEF were significantly higher than in nonsensitized animals. Fibrinolytic (plasminogen activator [PA]) activity was detected in the MEF; however, only a small level of activity of nonspecific proteases was detected because of the significant level of antitryptic activity in the MEF. The levels of protease inhibitors and PA activity were significantly reduced by the steroid treatment. It is concluded that protease inhibitors play an important role in the protection of the middle ear mucosa and that corticosteroid treatment can reduce the severity of IC otitis media.
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PMID:Proteases and protease inhibitors in immune complex otitis media in chinchillas. 247 73

Phospholipase activation with resulting phospholipid breakdown and lipid byproduct accumulation may play a critical role in hypoxic cell injury. To explore this role, mildly hypoxic rabbit renal proximal tubules (PT) in suspension were treated in vitro with exogenous phospholipase A2 (PLA2). This treatment produced severe tubule cell injury measured by alterations in tubule cation homeostasis, respiratory rates, and adenosine nucleotide metabolism. This injury was associated with loss of the major membrane phospholipids, phosphatidylcholine (PC) and phosphatidylethanolamine (PE), with accumulation of lipid byproducts, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), and free fatty acids (FFA). Addition of fatty acid-free bovine serum albumin (BSA) to PTs reduced markedly FFA levels and improved significantly derangements in metabolic parameters of hypoxic PTs treated with exogenous PLA2, suggesting that FFA accumulation was a critical factor in this injury process. Effects of increasing durations of hypoxia (30, 45, and 60 min) with or without reoxygenation recovery demonstrated increased FFA levels, especially polyunsaturated FFA, which correlated better with the degree of hypoxic injury than alterations in membrane phospholipid and lysophospholipid levels. PTs undergoing hypoxia and reoxygenation recovery exposed to BSA were not protected. Although 60 min of hypoxia with 60 min reoxygenation produced accumulation of FFA to levels nearly identical to those seen in hypoxic PTs treated with exogenous PLA2 and BSA, with a similar distribution of various FFA species, hypoxia/reoxygenation produced a more severe degree of cell injury than that observed with hypoxia plus exogenous PLA and BSA.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The role of free fatty acids in hypoxia-induced injury to renal proximal tubule cells. 270 39

Activation of the plasma zymogen plasminogen to the enzyme plasmin by the early bovine embryo was evaluated. Sixteen-cell embryos to early morulae were collected at death from handmated synchronized and superovulated crossbred beef cows. Embryos were cultured in Ham's F-12 medium supplemented with 15 mg/ml bovine serum albumin containing 0, 15, 30, 60 or 120 micrograms/ml plasminogen in a humidified atmosphere of 5% CO2 in air at 37 degrees C. Cultures were observed every day, and stage of development was recorded. Medium was collected at 24-h intervals, starting at initiation and continuing through 288 h of culture. Plasminogen activator and plasmin levels in the culture media were determined, using a caseinolytic assay. The percentages of embryos developing to the initiating hatching blastocyst, hatched blastocyst, attached blastocyst, and attached blastocyst with trophoblastic outgrowth stages were not significantly different between the five levels of plasminogen. Initiation and completion of hatching, however, accelerated as plasminogen concentration increased in the culture media. Plasminogen activator production, expressed as milliunits X ml-1 X h-1 X viable embryo-1, was low for the first 48 h of culture, increased between 48-120 h, and tended to plateau thereafter. Plasminogen activation, measured indirectly as the plasmin concentration in a microdrop of medium and expressed as microgram plasmin X ml-1 X h-1 X viable embryo-1, followed plasminogen activator production, and was consistently low for the first 48-72 h of culture. Embryonic activation of plasminogen increased sharply thereafter, and also plateaued after 120 h.
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PMID:Activation of plasminogen by the early bovine embryo. 295 97

Callus formation in the periosteal bone interface in response to bone morphogenetic protein (BMP) and associated bone matrix noncollagenous proteins (BMP/NCP) was investigated in mature adult rabbits. For controls byproducts of BMP/NCP purification, bone marrow, eight nonskeletal tissues, purified matrix gamma-carboxyglutamic acid-rich protein (MGP), and a composite of BMP/NCP and polylactic-polyglycolic acid polymer (PLA/PGA) were also implanted in the periosteal bone interface. Quantitative microcomputer image analysis and histologic studies were performed three weeks after the implantation. BMP/NCP and bone marrow or BMP/NCP implanted over a single drill hole into the marrow cavity produced three times more new bone than the bone marrow alone. BMP/NCP alone produced twice as much new bone as bone marrow alone. Control implants of bovine serum albumin or purified MGP produced no new bone. Autogeneic minced muscle and ten nonskeletal tissue controls produced little or no bone formation. Even at one-fifth of the dose of BMP/NCP, a composite of PLA/PGA incorporating BMP/NCP showed almost the same amount of new bone as BMP alone. Histologically, the response to BMP/NCP consisted of an external callus of calcifying cartilage and woven bone. The response to subperiosteal implants of BMP/NCP or BMP/NCP with bone marrow or with minced muscle occurred with the same sequence of developmental events as seen either in embryonic skeletogenesis or in fracture callus.
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PMID:Induction of callus formation by implants of bone morphogenetic protein and associated bone matrix noncollagenous proteins. 318 May 78

The excretory duct of the lacrimal gland of rabbits and guinea pigs was cannulated in situ for collection of pure lacrimal gland fluid, not contaminated by secretions from the Harderian gland or contributions of desquamating cells of the conjunctival and corneal epithelium. Tears as well as lacrimal gland fluid of both species showed a species-specific and molecular weight-dependent pattern after sodium dodecylsulphate-polyacrylamide (SDS-PAA) gradient slab gel electrophoresis. The most striking difference in both species was a protein corresponding to serum albumin present in tears and almost lacking in lacrimal gland fluid. Likewise, a variety of enzymes, total protein and PGE2 were measured in tears and lacrimal gland fluid. For rabbit tears the lacrimal gland is the primary tissue source of lysozyme (LZM), beta-hexosaminidase (beta-hex), angiotensin-converting enzyme (ACE), plasminogen activator (PA) and total protein, while lactate dehydrogenase (LDH) and the greater part of prostaglandin E2 (PGE2) are present in rabbit tears mainly as products from other ocular tissue sources. In guinea pig tears peroxidase (POD), ACE, PA and less PGE2 are exceted by the lacrimal gland, amylase (AMY), LDH and a substantial amount of PGE2 are added to the guinea pig tears by other ocular tissue sources. Beta-hex and total protein are released from the lacrimal gland and from other ocular tissue sources as well.
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PMID:Comparison of tears and lacrimal gland fluid in the rabbit and guinea pig. 386 12

Plasma and urine fibrinolysis were studied in 36 patients with glomerulonephritis and proteinuria. In 40% of these plasma fibrinolytic activator activity was moderately reduced and fibrinolytic inhibitors were increased. Globulins with antiplasmin effect were raised, particularly in the earlier months. Both the serum cholesterol and the plasma fibrinogen were related to the level of serum albumin, and those patients with high fibrinogen levels were also those with poor plasma fibrinolytic activator and those showing a steady deterioration. Urinary fibrinolysis was greatly reduced in most patients and bore no relation to plasma fibrinolysis levels. Hence urokinase is not derived from circulating plasminogen activator.
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PMID:Study of proteins and fibrinolysis in patients with glomerulonephritis. 424 92


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