Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.23.5 (cathepsin D)
 4,130 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

These experiments test whether creatine, a product of muscular contraction, stimulates myofibrillar protein synthesis. It was found that skeletal muscle cells formed both in vitro and in vivo and cardiac muscle cells formed in vivo synthesize myofibrillar proteins faster when supplied creatine in vitro. The rates of synthesis and/or accumulation of three myofibrillar proteins-myosin heavy chain actin, and creatine kinase-were stimulated by creatine. In contrast, the rates of synthesis of total protein and of deoxyribonucleic acid (DNA) and the activities of several nonmyofibrillar enzymes were not altered by creatine. These include lactic dehydrogenase, cathepsin D, acid phosphatase, and beta-acetylglucosaminidase. It is concluded that creatine selectively stimulated the rate of synthesis of contractile proteins in skeletal and cardiac muscle in vitro and may play a role in muscle hypertrophy.
 ...
PMID:Creatine: a possible stimulus skeletal cardiac muscle hypertrophy. 12 40

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.
 ...
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.
 ...
PMID:beta-Glucuronidase activity in trained red and white skeletal muscle of mice. 21 65

A rabbit model was used to determine the effects of prostaglandins and arachidonic acid on cellular integrity and survival during endotoxic shock. Prostaglandins A2, E1 and F2alpha were infused intravenously at a rate of 1.0 microgram/kg/min for 105 min beginning 15 min after the administration of an LD60 dose of Escherichia coli endotoxin. While each of the prostaglandins tested significantly attenuated the accumulation of lactic acid dehydrogenase in the plasma of shocked animals, none were able to protect against the increase in the plasma activities of glutamic pyruvic transaminase or cathepsin D during the shock state. Prostaglandins A2, E1 and F2alpha did not significantly enhance the survival of the treated animals as compared to vehicle-treated controls. In contrast, arachidonic acid 15 microgram/kg/min i.v.) significantly prevented the accumulation of lactic acid dehydrogenase and glutamic-pyruvic transaminase activities in the plasma of shocked animals, and also significantly increased the number of survivors in this group 48 hours after the endotoxin administration. In summary, while the treatment of endotoxic rabbits with prostaglandins of the A, E and F series was of no survival value, the treatment of these animals with a substrate of the prostaglandin synthetase complex resulted in a dramatic increase in the survival rate. The mechanism of action of arachidonic acid in this regard is not clear.
 ...
PMID:Endotoxic shock in the rabbit: the effects of prostaglandin and arachidonic acid administration. 35 77

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.
 ...
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.
 ...
PMID:Anti-endotoxin actions of methylprednisolone in the isolated perfused cat liver. 69 67

Changes in liver integrity were studied in isolated perfused cat livers during simulated shock conditions (i.e., combined hypoxia, acidosis, and ischemia) or under the influence of each hypodynamic state separately. The combined hypodynamic stimuli depressed carbon clearance 51% and significantly elevated lactic acid dehydrogenase (LDH) and cathepsin D activities in the perfusate. The perfused liver was more seriously affected by hypoxia than by acidosis or ischemia alone. Reticuloendothelial clearance was depressed 20% and 25% in acidosis and hypoxia, respectively. Hypoxia also induced a 3-fold increase in cathepsin D and a 13-fold increase in LDH activities in the perfusate. After 150 min of hypoxia or ischemia, free cathepsin D in liver tissue increased significantly. The impairment of liver cell integrity (i.e., of Kupffer and parenchymal cells) occurred between 60 and 90 min during simulated shock conditions, indicating that the liver is stable for 60 min when it is exposed to hypoperfusion. The perfused liver is sensitive to local stimuli that predominate in circulatory shock, particularly hypoxia. These stimuli promote the release of lysosomal and cytoplasmic enzymes as well as depress phagocytosis by the reticuloendothelial system, phenomena that exacerbate the shock state.
 ...
PMID:Hepatic cell integrity in hypodynamic states. 99 83

Samples of subretinal fluid (SRF) from patients with primary rhegmatogeneous retinal detachment of various duration were studied using standard enzymologic techniques. The protein content in SRF increased with the duration of detachment. The activities of lysosomal enzymes in SRF, which were acid phosphatase, beta-glucuronidase, and cathepsin D, also increased with the duration of detachment. Especially cathepsin D, which was not detected in serum, was present in SRF. The activity of a nonlysosomal enzyme, i. e., lactic dehydrogenase, which was used as a marker of cell disruption and of serum transudation was the same as that of serum. Because lysosomal enzymes are known to be able to degrade cells and tissues, the enzymologic analysis of SRF contributes to our understanding of the pathology of primary rhegmatogeneous retinal detachment.
 ...
PMID:Lysosomal enzymes in subretinal fluid. 108 77

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.
 ...
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.
 ...
PMID:Selective presence of acid hydrolases in the interphotoreceptor matrix. 261 85


1 2 3 4 Next >>