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)

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

Vascular smooth muscle (VSM) cells from hypertensive and normotensive rat aortae and caudal arteries were isolated by enzymatic techniques, homogenized, and fractionated by differential pelleting. By these techniques, only mitochondria could be enriched more than fivefold in any one fraction. The other organelles were distributed heterogeneously in almost all fractions. Hypertensive smooth muscle enzyme distribution patterns were different from the normotensive, suggesting that changes in sedimentation characteristics had occurred. Activity of the enzyme 5'-nucleotidase increased in whole tissue homogenates and in the 'microsomal' fraction of aortic and caudal artery of hypertensive VSM. The lysosomal protease, cathepsin D, of hypertensive animals decreased in activity for both vascular smooth muscles while N-acetyl-beta-glucosaminidase and pNPPase (acid phosphatase) increased. The possibility of a functional deficiency in protein degradation causing lysosomal overloading is discussed.
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PMID:Alterations in lysosomes, catalase-containing organelles, mitochondria and plasma membrane fragments from hypertensive rat aorta and caudal artery. 21 41

Isoelectric focusing was used to investigate the multiple forms of acid phosphatase, arylsulfatase, beta-glucuronidase, beta-galactosidase and beta-N-acetylhexosaminidase in the following, previously characterized subcellular fractions from rat kidney: a special rough microsomal fraction, enriched up to 9-fold over the homogenate in acid hydrolases; a smooth microsomal fraction; a Golgi membrane fraction enriched about 2.5-fold in acid hydrolases and 10- to 20-fold in several glycosyl transferases; and a lysosomal fraction enriched up to 25-fold in acid hydrolases. The electro-focusing behavior of the hydrolases in these fractions was markedly sensitive to the autolytic changes that occur under acidic conditions, even at 4 degrees C. Autolysis was minimized by extracting fractions in an alkaline medium (0.2% Triton X-100, 0.1 M sodium glycinate buffer, pH 10, 0.1 % p-nitrophenyloxamic acid) and adding p-nitrophenyloxamic acid (0.1 %), AN INHIBITOR OF LYSOSOMAL NEURAMINIDASE AND cathepsin D, to the pH gradient. The enzymes in the lysosomal fraction displayed a characteristic bimodal or trimodal distribution. Arylsulfatase, beta-glucuronidase and beta-N-acetylhexosaminidase occurred in an acidic form with an isoelectric point of 4.4, and a basic form with an isoelectric point of 6.2, 6.7 and 8.0, respectively. Acid phosphatase and beta-galactosidase occurred in an acidic, intermediate and basic form with isoelectric points of about 4. 1, 5.6 and 7.4, respectively. In the special rough microsomal fraction these enzymes were mostly in a basic form with isoelectric points between 7.5 and 9; these were 1-2 units higher than the corresponding basic forms in the lysosomal fraction. Treatment of extracts of the rough microsomal fraction with bacterial neuraminidase raised the isoelectric points of all five hydrolases by 1-2.5 units, indicating the presence of some N-acetylneuraminic acid residues in these basic glycoenzymes. The hydrolases in the Golgi fraction were largely in an acidic form with isoelectric points similar to or lower than those of the corresponding acidic components in the lysosomal fraction. The hydrolases in the smooth microsomal fraction showed isoelectric-focusing patterns intermediate between those in the rough microsomal and the Golgi fractions. These findings support the following scheme for the synthesis, transport and packaging of the lysosomal enzymes. Each hydrolase is synthesized in a restricted portion of the r
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PMID:Changes in electronegativity of lysosomal hydrolases during intracellular transport. An isoelectric-focusing study in subcellular fractions of rat kidney. 23 56

Intact and viable parenchymal and non-parenchymal liver cell preparations were isolated by enzyme perfusion techniques from young and old rats. The distribution of the lysosomal enzymes acid phosphatase, beta-galactosidase, cathepsin D, acid DNAse, and arylsulphatase B over parenchymal and non-parenchymal cells was determined. In addition, morphological and morphometric changes which occur in parenchymal cells with age were investigated. All lysosomal enzymes studied are present in both cell classes, but non-parenchymal cells possess much ligher activities per mg protein than do parenchymal cells. This phenomenon is most pronounced for cathepsin D with a 13-times higher specific activity in non-parenchymal cells. Electron microscopic observations demonstrated that the lysosomal activities in non-parenchymal cells can be attributed mainly to the large and numerous lysosomal structures in Kupffer cells. Parenchymal cells from old rats have higher lysosomal enzyme activities per mg protein than do hepatocytes from young rats. This observation is in agreement with the general increase with age in the cytoplasmic volume fraction occupied by lysosomal structures in parenchymal cells. In general, non-parenchymal cells show no increase in specific enzyme activities with age. The results obtained suggest an increase in the heterogeneity--in both appearance and enzyme content--of the lysosomal structures in parenchymal cells with age.
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PMID:Changes in lysosomes during ageing of parenchymal and nonparenchymal liver cells. 23 90

Lucite chambers, applied to antral and proximal duodenal mucosae with blood supply intact, were used to compare ionic flux and the total, labilized activity of several acid hydrolases including cathepsin D, alpha and beta-galactosidase, beta-N-acetyglucosaminidase, arylsulfatase, and acid phosphatase. Insorption of H+ ion by the antrum is increased by the application of aspirin-acid-salt solution, which also stimulates acid hydrolase activity; acute erosions develop very rapidly. On the other hand, H+ ion is much more rapidly removed from chambers applied to the duodenal mucosa, isolated by the chamber from bile and pancreatic secretions. The same aspirin-acid-salt solution reduces net H+ ion loss from the duodenal chamber, depresses levels of the acid hydrolases, and no ulcers develop.
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PMID:Effect of aspirin on ionic movement and acid hydrolase activity of explants of canine antral and duodenal mucosae. 23 98

Because protein degradation in liver and skeletal muscle is increased by thyroid hormones and decreased by thyroidectomy; we investigated the influence of thyroid hormones on the level of lysosomal enzymes. Hypophysectomized rats received daily injections of L-thyroxine or L-triiodothyronine. After 3 days of this regimen, homogenates of liver and skeletal muscle showed a 2- to 3-fold increase in the activities of cathepsin D, cathepsin B, and other lysosomal enzymes including leucine aminopeptidase, acid phosphatase, beta-galactosidase, N-acetylglucosaminidase, and alpha-mannosidase. In liver, this effect reflected increased enzyme activity in the two subcellular fractions that normally contain lysosomes. Titration of cathepsin D with pepstatin indicated that the increase in this activity resulted from an increase in the number of enzyme molecules. These effects occurred with both pharmacologic (thyrotoxic) and physiologic (growth-promoting) doses of thyroid hormones. Liver and skeletal muscle from thyroidectomized rats had approximately 50% of the normal levels of lysosomal enzyme activities. Under these various conditions, heart and kidney, tissues in which protein degradation does not appear to be influenced by thyroid hormones, showed no significant changes in lysosomal hydrolases. Thus, thyroid hormones regulate proteolytic and other lysosomal enzyme activities in those tissues in which these hormones influence protein degradation. Many characteristic features of hyperthyroidism and hypothyroidism may result from changes in levels of lysosomal enzymes.
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PMID:Thyroid hormones control lysosomal enzyme activities in liver and skeletal muscle. 27 25

The reliability of enzyme histochemical semipermeable membrane techniques for the demonstration of acid hydrolases was investigated with a combined histochemical and biochemical study. In part 1 the histochemical findings were presented. In this communication the biochemical findings are reported and compared with the histochemical findings. In m. soleus, m. plantaris, m. gastrocnemius and diaphragm of vitamin E deficient rabbits the activity of the lysosomal acid hydrolases, cathepsin D, acid maltase, acid phosphatase and beta-glucuronidase is significantly increased. This increase in activity of the investigated acid hydrolases was equal for muscles with an aerobic or an anaerobic metabolism. By means of statistical calculations the activity of the enzymes demonstrated with histochemical techniques was compared with the enzyme activity determined with biochemical techniques. From the results of this investigation it can be concluded that the histochemical semipermeable membrane techniques for the demonstration of activity of acid hydrolases are very reliable. Considering the fact that these techniques are also tissue-saving, they are therefore extremely suitable for the study of catabolic wasting processes in skeletal muscle tissues of patients with inherited or acquired muscular diseases.
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PMID:Evaluation of histochemical observations of activity of acid hydrolases obtained with semipermeable membrane techniques: a combined histochemical and biochemical investigation 2. The biochemical investigation and comparison with the histochemical observations. 35 51

The reliability of enzyme histochemical observations of activities of acid hydrolases was investigated with a combined histochemical and biochemical study. Specimens of m. soleus, m. plantaris, m. gastrocnemius and diaphragm of normal and of vitamin E deficient rabbits were used. For the histochemical investigation, activity and localization of acid phosphatase, beta-glucuronidase, leucine aminopeptidase and E600 resistant non-specific arylesterase were examined with semipermeable membrane techniques. For the biochemical investigation, activity of acid phosphatase, beta-glucuronidase, cathepsin D, acid maltase and neutral maltase was determined. By means of stastical calculations the enzyme activities demonstrated with histochemical techniques were compared with the enzyme activities determined with biochemical techniques. In the present communication the histochemical findings are reported and discussed. From the histochemical findings it appeared that activity of the acid hydrolases investigated is strongly increased in both a granular and a diffuse pattern in skeletal muscle of vitamin E deficient rabbits. The statistical calculations of the histochemical findings clearly reveal that the increased activity of one acid hydrolase was highly significantly paralleled by an increased activity of a second acid hydrolase. Moreover the probability that the activity of all other histochemically studied acid hydrolases was significantly increased was rather high. The increase in activity of the acid hydrolases studied was the same in muscles with an aerobic or an anaerobic metabolism. Moreover there was no difference in activity and localization of the acid hydrolases in aerobic type I and anaerobic type II fibres. The localization of acid phosphatase and beta-glucuronidase activity muscle fibres mostly coincided. In cases where these enzymes were localized both centrally and in the subsarcolemnal areas of the muscle fibres, the activity of E600 resistant naphtholesterase was usually, and the activity of leucine aminopeptidase was exclusively located in the subsarcolemnal areas. All of the examined acid hydrolases were found to be present in the inflammatory exudate and in the connective tissue.
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PMID:Evaluation of histochemical observations of activity of acid hydrolases obtained with semipermeable membrane techniques: a combined histochemical and biochemical investigation 1. The histochemical investigation. 35 53

The activity of cathepsin B was assayed in murine resident peritoneal macrophages, and after stimulation of the cells in vivo and in vitro. The resident cells showed a very low activity of the enzyme, compared to the activities of three other lysosomal enzymes: cathepsin D, acid phosphatase, and beta-glucuronidase which were tested simultaneously. Endocytosis of carrageenan, latex, or carbon particles in vitro induced a prominent rise in intracellular cathepsin B activity. Addition of endotoxin from Escherichia coli in vivo or in vitro, or cell wall products from streptococci in vitro caused no change in cathepsin B activity. There was a release of enzyme activity to the medium after a 72-hour culture of macrophages. However, the release, calculated as a percentage of total activity, was not influenced by any treatments mentioned. All significant rises in enzyme activity could be inhibited by the addition of cycloheximide, and it was concluded that increased enzyme activity was dependent on new protein synthesis.
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PMID:Cathepsin B activity in stimulated mouse peritoneal macrophages. 38 72

Morphology, lysosomal enzyme activities, and phagocytosis via immunological receptors were tested in peritoneal macrophages from germfree and conventional mice. Nonstimulated macrophages from germfree mice showed less spreading and were more easily detached when seeded on glass than conventional macrophages. The activities of the lysosomal acid phosphatase and cathepsin D were similar in the two cell groups, whereas beta-glucuronidase showed higher activity in macrophages from germfree mice. F(c) receptor-mediated phagocytosis of opsonized sheep erythrocytes was equally effective in germfree and conventional macrophages, and both cell types attached but did not internalize erythrocytes via the C(3)b receptor. Intraperitoneal injections of mineral oil caused a significantly higher influx of macrophages in conventional mice than in germfree mice, whereas the influx of polymorphonuclear cells was enhanced in both animals. Stimulation in vivo with oil or Escherichia coli endotoxin increased cell size, spreading ability, membrane ruffling, and lysosomal enzyme activities in macrophages from both conventional and germfree mice. The Fc-mediated phagocytosis was not influenced by stimulation, whereas the capacity to internalize via C(3)b receptor was triggered in macrophages from conventional mice, but not in corresponding cells from germfree mice. Similar results were obtained after stimulation with endotoxin in vitro. Culture in fetal calf serum for 72 h caused intracellular rises in all three enzyme activities tested in macrophages from conventional mice, whereas only the activity of acid phosphatase was increased in macrophages from germfree mice. Stimulation with zymosan in vitro caused selective release of lysosomal enzyme activity in macrophages from both animal groups. We conclude that peritoneal macrophages from germfree mice share several properties with cells from conventional mice, however, unstimulated beta-glucuronidase activity was increased, whereas spreading on glass, chemotactic response, in vitro induction of lysosomal enzymes, and the capacity to internalize via the C(3)b receptor after stimulation were reduced or absent.
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PMID:Comparison of peritoneal macrophages from germfree and conventional mice. 39 29


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