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

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Query: EC:1.1.1.37 (malate dehydrogenase)
4,591 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1) A lysosomal protease, a new cathepsin that inactivates glucose-6-phosphate dehydrogenase [EC 1.1.1.49] and some other enzymes and differs from cathepsin B [EC 3.4.22.1] was purified about 2,200-fold from crude extracts of rat liver by cell-fractionation, freezing and thawing, acetone treatment, gel filtration, and DEAE Sephadex and CM-Sephadex column chromatographies. 2) The new cathepsin was markedly activated by the thiol-reagent, 2-mercaptoethanol and inhibited by monoiodoacetate. 3) The molecular weight of the new cathepsin was found by Sephadex G-75 column chromatography to be 22,000, which is smaller than that of cathepsin B. 4) The optimum pH of the enzyme for inactivation of glucose-6-phosphate dehydrogenase was pH 5.0--5.5. The enzyme was unstable in alkali and on heat treatment. 5) The rates of inactivation of glucose-6-phosphate dehydrogenase, apo-ornithine aminotransferase [EC 2.6.1.13], apo-tyrosine aminotransferase [EC 2.6.1.5], apo-cystathionase [EC 4.4.1.1], glucokinase [EC 2.7.1.2], glyceraldehyde-3-phosphate dehydrogenase [EC 1.2.1.12], and malate dehydrogenase [EC 1.1.1.37] by the new cathepsin were higher than those by cathepsin B. However aldolase [EC 4.1.2.13] was inactivated more rapidly by cathepsin B than by the new cathepsin. Lactate dehydrogenase [EC 1.1.1.27], glutamate dehydrogenase [EC 1.4.1.2] and alcohol dehydrogenase [EC 1.1.1.1] were not inactivated by either cathepsin. Unlike cathepsin B, the new cathepsin scarcely hydrolyzes N-substituted derivatives of arginine.
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PMID:Purification and properties of a new cathepsin from rat liver. 3 59

The effects of short-term (6 hours) pancreatic duct obstruction on the possible secretion of lysosomal enzyme into pancreatic juice and subcellular lysosomal and mitochondrial fragility were investigated in rabbits. Caerulein stimulated the secretion of amylase and cathepsin B into pancreatic juice in controls. Blockage of the pancreatic duct for 6 hours caused a significant decrease of amylase and cathepsin B output into pancreatic juice, and a significant rise in portal serum amylase and cathepsin B levels, and pancreatic amylase content and an accelerated leakage of cathepsin B from lysosomes and malate dehydrogenase from mitochondria in in-vitro preparations, as well as redistribution of cathepsin B in acinar cells. These changes tended to continue for up to 12 hours after removal of the pancreatic duct obstruction. These results indicate that under physiological conditions, lysosomal enzymes are secreted into the pancreatic juice in response to stimulation by gut hormones and that increased lysosomal fragility, mitochondrial fragility and impaired pancreatic energy charge levels are closely related to the pathogenesis of pancreatic injury in this model. Moreover, zymogen colocalized with lysosomal enzyme after duct obstruction was secreted into pancreatic juice in increased amount together with digestive enzymes; these findings suggest that lysosomal enzymes play important pathophysiological roles in pancreatic juice.
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PMID:Fragility of subcellular organelles induced by pancreatic duct obstruction in rabbits. 128 74

The redistribution of cathepsin B, a lysosomal enzyme, from the lysosomal pellet to the zymogen pellet in the subcellular fractionation, the colocalization of cathepsin B with digestive enzyme, and increased cellular, lysosomal, and mitochondrial fragility within acinar cells have been found during the early stages of caerulein-induced acute pancreatitis in rats. In the present study, the authors investigated the protective effects of prostaglandin E1 and E2, a combined therapy of these prostaglandins, and a new, synthetic, low molecular weight protease inhibitor, ONO3307, on the exocrine pancreas in this noninvasive model of experimental pancreatitis in vivo and in vitro. Prostaglandin E2, but not E1, prevented hyperamylasemia, congestion of amylase and trypsinogen in the acinar cells, redistribution of cathepsin B, and amylase and lactate dehydrogenase discharge from the dispersed acini. It also prevented cathepsin B leakage from the lysosomes and malate dehydrogenase leakage from the mitochondria in an almost dose-dependent manner, particularly at the dose of 100 micrograms/kg/hr continuous infusion. Furthermore, the combined therapy of prostaglandin E2 with ONO3307 strongly inhibited all the parameters tested in this study. This combination therapy seems to be the most effective against secretagogue-induced pancreatic injuries. These results indicate that cellular and subcellular organellar fragility seem to be closely involved in the pathogenesis of acute pancreatitis. Prostaglandin E2 seems to have important cytoprotective effects on the biologic membranes, such as a stabilizer of lysosomal or mitochondrial membranes. In addition, these findings also suggest the crucial roles of some unknown proteases in the etiology of acute pancreatitis, and indicate the clinical effectiveness of prostaglandins and this type of low molecular weight protease inhibitor for acute pancreatitis.
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PMID:Cytoprotective effects of prostaglandins and a new potent protease inhibitor in acute pancreatitis. 128 94

The study investigated the protective effect of a new synthetic protease inhibitor, E-3123, a 4-guanidinobenzoate methanesulphonate, on the exocrine pancreas in caerulein-induced pancreatitis of rats both in vivo and in vitro. Hyperamylasaemia, pancreatic oedema and congestion of amylase, as well as cathepsin B leakage from lysosomes and malate dehydrogenase leakage from mitochondria, were prevented by infusion of 5 mg/kg.h E-3123 particularly when infused for 2 h before and during 5 micrograms/kg.h caerulein infusion for 3.5 h. The results indicate that E-3123 plays its protective roles against pancreatitis in the subcellular compartments such as lysosomes and mitochondria, and that such a low molecular weight protease inhibitor as E-3123 may be clinically useful in the treatment of acute pancreatitis.
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PMID:A new synthetic protease inhibitor, E-3123, prevents lysosomal and mitochondrial fragility in rat caerulein-induced pancreatitis. 138 65

We studied the effect of short-term (3 h) pancreatic duct obstruction (PDO) on the exocrine pancreas and on the secretion of lysosomal enzymes into the pancreatic juice of rabbits during stimulation by pancreatic secretagogues. The following evaluations were made: serum amylase levels, pancreatic water content, pancreatic amylase, trypsinogen and cathepsin B content, and output of pancreatic enzymes and lysosomal hydrolases when stimulated by secretin and caerulein as well as the distribution of cathepsin B in subcellular fraction. Cellular fragility (LDH leakage from dispersed acini) and subcellular organellar fragility (cathepsin B leakage from lysosomes and malate dehydrogenase leakage from mitochondria) were also evaluated. PDO for 3 h plus secretin infusion caused a significant rise in serum amylase levels, pancreatic water content, and pancreatic amylase and trypsinogen content due to congestion of digestive enzymes during PDO. There was also a redistribution of cathepsin B from the lysosomal fraction to the zymogen fraction and increased cellular and subcellular organellar fragility. In normal rabbits and in those with only secretin infusion, caerulein stimulated the secretion of cathepsin B into pancreatic juice. Just after PDO, the secretion of cathepsin B, amylase and trypsinogen significantly decreased. By 24 h after PDO, the output of cathepsin B stimulated by caerulein and secretin had increased significantly. Amylase and trypsinogen output were also significantly increased at this stage, in both the secretin and caerulein fractions. These results indicate that the secretion of lysosomal enzymes into pancreatic juice is stimulated by gut hormones, such as caerulein, in the normal physiological state and in pathological states, such as PDO. These results also show an important role of increased cellular and subcellular organellar fragility in the pathogenesis of pancreatic injuries induced by PDO and augmented secretion of both lysosomal enzymes and pancreatic digestive enzymes in the recovery stage after PDO and their important roles at this stage. Lysosome enzymes also seem to play some physiological roles in the pancreatic ductal system in normal physiological states as well as their roles in pathological states, because cathepsin B can activate trypsinogen, and trypsin can activate many other enzymes.
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PMID:Effect of short-termed pancreatic duct obstruction on the pancreatic subcellular organellar fragility and pancreatic lysosomal enzyme secretion in rabbits. 138 8

To evaluate the effects of acute pancreatitis on the energy metabolism of the liver and on the fragility of hepatic cells and subcellular organelles, we studies (1) the arterial blood ketone body ratio (BKBR) (aceto acetate/beta-hydroxy butyrate), which is in equilibrium with the free NAD+/NADH ratio in liver mitochondria; (2) the hepatic energy charge (EC) = (ATP + 1/2 ADP)/(ATP + ADP + AMP); (3) the cathepsin B leakage from hepatic lysosomes and the malate dehydrogenase leakage from hepatic mitochondria in vitro; and (4) the protective effects of prostaglandin E2 (PGE2) and a new synthetic protease inhibitor ONO 3307 on hepatic injury in acute pancreatitis induced in rats by a supramaximal dose of caerulein. Decreased BKBR and hepatic EC as well as increased hepatic lysosomal and mitochondrial fragility were observed in rats with this type of acute pancreatitis, and both PGE2 and ONO 3307 had a significant protective effect against hepatic injury in these rats, especially ONO 3307. These results suggest that impaired hepatic energy metabolism is closely related to increased hepatic lysosomal and mitochondrial fragility and that some proteases, which are derived from pancreatitis and are susceptible to inhibition by ONO 3307, seem to play an important pathological role in this liver injury induced by pancreatitis. Therefore, it is important to take care of the liver in patients with acute pancreatitis.
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PMID:Impaired hepatic energy metabolism in rat acute pancreatitis: protective effects of prostaglandin E2 and synthetic protease inhibitor ONO 3307. 152 49

The present study investigated the protective effect of a new potent synthetic protease inhibitor, E-3123 (4-guanidinobenzoate methanesulfonate) on the exocrine pancreas in the caerulein induced experimental pancreatitis both in-vivo and in-vitro at 3 different doses (1, 2, and 5 mg/kg.hr). This protease inhibitor prevented hyperamylasemia, pancreatic edema, congestion of amylase, and both amylase and lactic dehydrogenase (LDH) discharge from dispersed acini, as well as cathepsin B leakage from lysosomes and malate dehydrogenase (MDH) leakage from mitochondria in a dose-dependent manner, particularly in doses of 2 and 5 mg/kg.hr. Furthermore, the combined prophylactic and therapeutic use of this agent seems to be very effective in preventing caerulein induced pancreatitis. These results indicate that E-3123 plays its protective roles against pancreatitis in the subcellular compartment: lysosomes, mitochondria, cellular or organella membranes. It is hoped that such a low molecular weight protease inhibitor as E-3123 will be clinically useful in the treatment of acute pancreatitis.
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PMID:A new synthetic protease inhibitor, E-3123, reduces organelle fragility of acinar cells in rat caerulein pancreatitis. 182 13

When rats were given a supramaximal dose of caerulein (infused intravenously at 5 micrograms/kg.h for 4 h) they developed acute pancreatitis characterized by significantly raised amylase levels in the blood. In this model of acute pancreatitis, reduced gastric adenylate energy charge levels were observed, and the leakage of the lysosomal enzyme, cathepsin B, from gastric lysosomes and of the mitochondrial enzyme, malate dehydrogenase, from gastric mitochondria were both significantly accelerated compared with the control group. The intragastric administration of the anti-ulcer agent, teprenone, at a dose of 5 mg/kg (twice before caerulein infusion) significantly inhibited this gastric damage accompanying acute pancreatitis. These results suggest that gastric subcellular organelle fragility may play an important role in the pathogenesis of impaired gastric energy metabolism accompanying acute pancreatitis, and indicate the possible usefulness of teprenone in preventing this gastric damage.
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PMID:Gastric subcellular organelle fragility and impaired gastric energy charge levels in rats with caerulein-induced acute pancreatitis: protective effect of anti-ulcer agent, teprenone. 808 24

The effects of prostaglandin E2 on the fragility of cellular and subcellular organelles in caerulein-induced acute pancreatitis were investigated in rats. PGE2 at doses of 50 and 100 micrograms/kg/hr infused for 2 hours before and during caerulein (5 micrograms/kg/hr for 3.5 hours) infusion significantly prevented the increased discharge of both amylase and lactate dehydrogenase from dispersed acini, and the leakage of cathepsin B from lysosomes and of malate dehydrogenase from mitochondria in the subcellular fraction in vitro. These results suggest that PGE2 has a cytoprotective effect against caerulein-induced pancreatitis by stabilizing cell and lysosomal and mitochondrial membranes.
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PMID:Effect of prostaglandin E2 on cellular, lysosomal and mitochondrial fragility in caerulein-induced pancreatitis in rats. 827 Feb 35

The effects of short-termed (2 hours) obstruction of pancreatico-biliary duct (PBDO) and exocrine stimulation (IDH) by caerulein infusion (0.2 microgram/kg.hr) with systemic hypotension (SH) (30% reduction of mean arterial pressure for 30 min) on the exocrine pancreas were evaluated in the rat. PBDO and IDH with SH caused more significant rises in portal serum amylase, cathepsin B and malate dehydrogenase levels, and pancreatic water content as well as more significant redistribution of cathepsin B activity from the lysosomal fraction to the zymogen fraction in the subcellular fractionations than only PBDO, or PBDO with IDH, or PBDO with SH group. In addition, more accelerated lysosomal and mitochondrial fragility were observed in the PBDO and IDH with SH group. Moreover, PBDO and IDH with SH caused an activation of larger amount of trypsinogen in the pancreas compared with other groups (PBDO with IDH and PBDO with SH group). These results indicate that present model of short-termed PBDO and exocrine stimulation with systemic hypotension seems to be pertinent model for gallstone pancreatitis in humans, and that redistribution of lysosomal enzymes and subcellular organellar fragility seem to play an important role in the pathogenesis of pancreatic injuries by PBDO, particularly with exocrine stimulation and pancreatic ischaemia, probably via activation of trypsinogen to trypsin by lysosomal enzyme such as cathepsin B.
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PMID:A new experimental model for gallstone pancreatitis: short-termed pancreatico-biliary duct obstruction and exocrine stimulation with systemic hypotension in rats. 835 38


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