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:3.4.23.5 (cathepsin D)
4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different traning programmes. Of acid hydrolases assayed the activities of beta-glucuronidase and cathepsin D were increased independently of training intensity. Simultaneous histochemical observations on beta-glucuronidase and arylsulphatase activities in the contralateral m. rectus femoris showed more intense staining in red as compared to white muscle fibres. It is suggested that training affected the red fibres and that the applied level of loading was probably too low to cause major involvement of white fibres.
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PMID:Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities. 21 99

We studied the effects of prolonged running exercise (5 days a week, 1.5 h per day at a speed of 17.6 m/min) on the activity of some acid hydrolases (beta-glucuronidase, beta-N-acetylglucosaminidase, acid phosphatase and cathepsin D) and three enzymes of energy metabolism (cytochrome c oxidase, lactate dehydrogenase and creatine kinase) in the distal and in the proximal, the predominantly white and red parts, respectively, of the vastus lateralis-muscle from mice. The acid hydrolase activity levels were 1.24--1.69 higher in untrained red muscle compared to untrained white muscle. The light training applied increased the activity of beta-glucuronidase in both red and white muscle. No other significant training effects were observed in the enzyme activities measured.
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PMID:beta-Glucuronidase activity in trained red and white skeletal muscle of mice. 21 65

The isolated cat liver perfused at a constant flow with Krebs-Henseleit solution containing low-molecular-weight dextran was employed to ascertain the direct effects of hypoxia or endotoxin on hepatic integrity. Hypoxia resulted in large increases in circulating lactate dehydrogenase (LDH) activity and in amino-nitrogen concentration, whereas endotoxin at a dose of 0.75 microgram/gm liver wet weight resulted in only small changes in these variables after 150 minutes of perfusion. Perfusion pressure and perfusate pH did not change significantly in response to either intervention. Both hypoxia and endotoxin significantly compromised lysosomal stability as evidenced by large increases in circulating levels of cathepsin D, large increases in the nonsedimentable fraction of tissue cathepsin D (ie, increased percentage of free activity), and changes in the ultrastructural appearance of liver lysosomes associated with enhanced fragility (eg, swelling, increased vacuolization). Both interventions also significantly impaired phagocytosis by reticuloendothelial cells within the liver. However, neither intervention altered BSP clearance, indicative of a lack of effect on parenchymal cell clearance. These findings indicate that both endotoxin and hypoxia induce direct cellular damage within the liver; however, endotoxin exerted a more selective action on lysosomes, whereas hypoxia produced more of a diffuse cytotoxic effect.
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PMID:Comparison of the cytotoxic actions of hypoxia and endotoxin in the perfused cat liver. 66 47

The efficacy of the synthetic glucocorticoid, methylprednisolone, was examined in vitro using an isolated cat liver perfused with a blood-free medium. Addition of endotoxin (75 microgram/g tissue) to the perfusate did not change perfusion pressure or total oxygen consumption. However, cellular integrity was severely compromised as reflected by increases in perfusate lactate dehydrogenase and cathepsin D activities, increases in tissue lysosomal fragility, and enlargement and vacuolization of lysosomes. Addition of methylprednisolone (1 x 10(-3) M) to the perfusion medium prevented the endotoxin-induced changes in hepatocyte integrity. It is suggested that a major action of endotoxin in the liver is to increase lysosomal fragility, and the protective action of methylprednisolone appears to be related to its lysosomal stabilizing action. The potent anti-endotoxin action of glucocorticoids in vivo may be due in part to the stabilization of lysosomal membranes in tissues such as the liver.
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PMID:Anti-endotoxin actions of methylprednisolone in the isolated perfused cat liver. 69 67

We examined the effects of tiapamil, a Ca2+ antagonist, on infarct size, lymphatic enzyme release, and arrhythmias in reperfused, ischemic canine hearts. Three-hour reperfusion of the left anterior descending coronary artery, which had been ligated for 3 h, significantly increased cardiac lymphatic release of lactate dehydrogenase (LDH), cathepsin D and creatine phosphokinase (CPK), and the incidence of ventricular premature contractions (VPCs), the increases being markedly higher than those in ligation period. Tiapamil, at the i.v. dose of 3 mg/kg/h for 6 h during the ligation and reperfusion periods markedly reduced these increases in lymphatic levels of LDH and cathepsin D and in VPCs, and significantly decreased infarct size. Tiapamil treatment only during the ligation period had similar preserving effects, but tiapamil treatment only during reperfusion did not. These results suggest that blockade of the Ca2+ channel must be achieved during the early phase of an ischemic episode in order to prevent myocardial deterioration during reperfusion.
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PMID:Protection by the calcium antagonist tiapamil, against cardiac lymphatic enzyme leakage and arrhythmias in canine hearts during reperfusion. 241

Adler and Martin (1983, Curr. Eye Res. 2, 359-66) found cathepsin D to be present in crude preparations of bovine interphotoreceptor matrix (IPM). The purpose of the present study was to determine, by investigating several acid hydrolases in purer IPM samples, whether hydrolytic enzymes abundant in RPE lysosomes were present also as normal components of the IPM. IPM was prepared from bovine eyes by the introduction of a small bleb of buffer between the neural retina and the RPE. These IPM samples were free from significant contamination by surrounding tissues; they contained IRBP as their only major protein, and had negligible amounts of lactate dehydrogenase and ROS-specific proteins. Most acid hydrolases were assayed fluorometrically by measuring the 4-methylumbelliferone released upon hydrolysis of appropriate derivatives; the substrate for cathepsin was hemoglobin. The amounts of the enzymes found in the IPM were far from uniform and could not be correlated with enzyme activities in either RPE or retina homogenates. The hydrolases in the IPM varied in amount from beta-galactosidase (28% of the RPE level), through N-acetyl-beta-glucosaminidase (20%), alpha-fucosidase (15%), beta-glucuronidase (12%), alpha-glucosidase (8%), cathepsin D (7%), alpha-mannosidase (7%), down to beta-glucosidase, acid phosphatase, and acid lipase (trace amounts, less than 1%). These results agree with the relative amounts of enzymes found by Wilcox (1987) to be secreted into the medium by cultured human RPE cells. Furthermore, the rank order of hydrolases in the IPM is the same as that for hydrolases secreted (but not recaptured) by human fibroblasts in I-cell disease. The conclusion from these correlations is that lysosomal enzymes are probably secreted, as a normal process, by the RPE into the IPM, where they may have a role in digesting shed outer segments and in catabolizing IPM components.
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PMID:Selective presence of acid hydrolases in the interphotoreceptor matrix. 261 85

Casein-induced amyloidosis in hamsters was found to be of the AA-type, as shown by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and amino acid analysis of the major low-molecular weight component of the amyloid fibrils. Levels of serum amyloid A (SAA) and the activities of cathepsin D, beta-N-glucosaminidase, serine esterase, lactate dehydrogenase (LDH) and gamma glutamyl transpeptidase (GGT) were measured in the blood plasma during induction of amyloidosis. During the pre-amyloid phase an increase was observed in all these parameters. During the deposition of amyloid, an increase was observed in the activities of the lysosomal enzymes cathepsin D and beta-N-glucosaminidase, which was significantly correlated with amyloid deposition. Serine esterase activities did not show any relationship to amyloid deposition. LDH and GGT activities were normal in the amyloid phase. SAA levels were lower during amyloid deposition than during the pre-amyloid phase. These findings indicate that a specific release of lysosomal contents from mononuclear phagocytic cells is involved in the pathogenesis of AA-amyloidosis. Amyloid deposition may be the result of: (i) extrusion of intralysosomal protein AA or pre-amyloid, followed by extracellular formation of amyloid fibrils; (ii) secretion of lysosomal enzymes, followed by extracellular cleavage of SAA and subsequent aggregation of protein AA with other components.
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PMID:Activities of lysosomal enzymes and levels of serum amyloid A (SAA) in blood plasma of hamsters during casein induction of AA-amyloidosis. 286 Sep 18

As a first step in studies on the molecular mechanism(s) underlying gentamicin toxicity, the effect of treating rats with this aminoglycoside antibiotic (100 mg/kg once or twice daily for 3 days) on the analytical subfractionation of the kidney cortex has been examined. DNA was used as a marker for the nuclei, cytochrome oxidase for mitochondria, acid phosphatase for lysosomes, catalase for peroxisomes (with reservations; see the companion paper), NADPH-cytochrome c reductase for the endoplasmic reticulum, p-nitrophenyl-alpha-mannosidase (at pH 5.5) for the Golgi apparatus, AMPase for the plasma membrane in general and alkaline phosphatase for the brush border, and lactate dehydrogenase for the cytosol. In addition, the presumptive lysosomal hydrolases N-acetyl-beta-D-glucosaminidase, p-nitrophenyl-alpha-mannosidase (at pH 4.5), cathepsin D, and DNase II were monitored. Electron microscopy was also performed on the subfractions obtained. The only significant biochemical changes brought about by gentamicin treatment were that N-acetyl-beta-D-glucosaminidase demonstrated both a greater total activity and a larger enrichment in the 104,000gav pellet, while p-nitrophenyl-alpha-mannosidase at pH 4.5 demonstrated the same total activity and a greater enrichment in the 104,000gav pellet. Since myeloid bodies were shown by electron microscopy to sediment primarily with the 500gav and 10,000gav pellets, the biochemical changes seen cannot be associated with these morphological structures. These findings suggest that selective changes in a certain subpopulation(s) of lysosomes or in certain lysosomal enzymes may be involved in the early stages of gentamicin toxicity. On the other hand, no lysosomal membrane damage was observed here, since both the latency of acid phosphatase and the recovery of this activity in the soluble cytosol were unchanged. The present investigation may also have relevance for the dosage and duration of gentamicin treatment chosen in clinical situations.
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PMID:Biochemical effects of gentamicin on rat kidney cortex. II. Analytical subfractionation after short-term, high-dose treatment. 303 Aug

The effects of two new calcium entry blockers, anipamil and ronipamil, were studied during 150 min of normoxic or hypoxic perfusion in isolated perfused cat livers. Hypoxic livers in which the vehicle for these inhibitors (i.e., ethanol) was injected intravenously prior to isolation of the liver, exhibited significantly higher increases in perfusion pressure, perfusate lactate dehydrogenase and cathepsin D activities, compared to control normoxic perfused livers. In contrast, the livers isolated from cats pretreated with calcium entry blocker anipamil and subsequently perfused under hypoxic conditions showed no significant difference in any of these variables from the control normoxic perfused livers. Ronipamil given intravenously 30 minutes prior to isolation also significantly protected the liver during hypoxia. The protection afforded by anipamil and ronipamil appears to be related to their inhibition of Ca++ influx which has been linked to cell death in hepatocytes.
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PMID:Beneficial actions of two novel calcium entry blockers in the isolated perfused hypoxic cat liver. 383 86

Young rats, fed a low calcium and vitamin D deficient diet for 2 weeks, developed hypocalcemia, an increased activity of serum alkaline phosphatase and an increase in the serum concentration of immunoreactive parathyroid hormone. An increased activity of lactate dehydrogenase and cytochrome oxidase in odontoblasts was found. No shift in the general energy metabolic pathway was found as visualized in the lactate dehydrogenase iso-enzyme pattern. The dominating lactate dehydrogenase isoenzyme in odontoblasts from both the normal and the deficient rats was LDH 1 (H4, LD5), thus indicating primarily an aerobic energy-metabolism Also the activities of the lysosomal enzymes acid phosphatase, cathepsin D and hyaluronidase in the odontoblasts from the deficient animals were increased when compared to the normal animals. No significant change could be demonstrated for beta-glucuronidase and beta-N-acetylglucosaminidase. It was earlier found that this deficient diet caused an increase in odontoblast alkaline phosphatase activities and protein synthesis in vitro. In view of the present findings it might be concluded that the low calcium and vitamin D deficient diet causes a general increase in the odontoblast metabolism. It is not known whether this is due to the increase in parathyroid hormone or if it is a direct effect of the lowered serum calcium concentration.
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PMID:Odontoblast metabolism in rats deficient in vitamin D and calcium. IV. Lysosomal and energy metabolic enzymes. 625 18


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