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)

Phenobarbital was given to male rats as a single injection and as repetitive injections for 7 days. The effects of treatment on the lysosomal hydrolases acid phosphatase, cathepsin D, and aryl sulfatase were analyzed at different intervals ranging from 1 to 15 days after seven injections, and from 1 to 48 h after a single injection. In both cases, microsomal protein and NADPH-cytochrome c reductase were measured to ensure proper induction. After a single injection, a slight decrease in hydrolytic activities was observed. Repetitive administration of phenobarbital gave rise to a marked decrease of lysosomal enzyme activities 1 day after cessation of treatment. This decrease was followed by a continuous increase in activity up to day 3 and 4. One or 2 weeks after treatment, enzyme activities declined to control values. The increase in activity of lysosomal hydrolytic enzymes was correlated with the onset of induced autophagy of endoplasmic reticulum membranes described as occurring in liver upon cessation of phenobarbital exposure. It is concluded that phenobarbital treatment per se decreases lysosomal enzyme activities, whereas the induced autophagy following cessation of exposure is associated with enhanced levels of lysosomal hydrolases in rat liver.
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PMID:Induction of liver lysosomal enzymes during the autophagic phase following phenobarbital treatment of rat. 40 31

Macrophages were obtained by pulmonary lavage from normal rabbits or rabbits that had developed pulmonary granulomas after receiving intravenous BCG vaccine 2-3 weeks earlier. The cells were disrupted in iso-osmotic sucrose and a low-speed supernatant was fractionated by isopycnic centrifugation on a linear sucrose density gradient. Three populations of hydrolase-containing granules (putative lysosomes) were found in both normal and BCG-induced macrophages. They were distinguished by their different distributions in the gradient and different sensitivities to disruption by digitonin and were termed:type A, containing lysozyme; type B, containing N-acetyl-beta-glucosaminidase, beta-glactosidase, beta-glucuronidase and possibly some lysozyme; type C, containing cathepsin D. Acid phosphatase appeared to be about equally distributed between type B and C granules. Type A and B granules from BCG-induced macrophages showed markedly greater equilibrium density than did those from normal macrophages. Beta-glucuronidase and acid phosphatase had greater specific activity in the induced cells.
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PMID:Analytical subcellular fractionation of alveolar macrophages from normal and BCG-vaccinated rabbits with particular reference to heterogeneity of hydrolase-containing granules. 45 80

The activities of the lysosomal acid hydrolases-cathespin D, acid phosphatase, beta-N-acetylglucosaminidase, and beta-glucuronidase-were measured in rat myometrium under the following hormonal conditions: during the estrus stage of the estrous cycle (NE); at 1,2, and 3 wk after ovariectomy; and in 3-wk postovariectomized females after hormone replacement therapy with 17 beta-estradiol (E2), progesterone (P), or E2 + P. Activities per milligram protein and per milligram DNA of the enzymes were significantly decreased after ovariectomy and were restored to the NE level or above after injecting E2 or E2 + P. Lysosomal enzyme activities did not change with hormonal state in hypophysectomized rats, suggesting that other hormones are required for mediation of enzyme activity. Acid hydrolase activities in other tissues and nonlysosomal enzyme activites in the myometrium did not fluctuate with hormonal state. Studies of lysosomal membrane integrity suggested that one population of lysosomes richer in cathepsin D and acid phosphatase and another rich in beta-N-acetylglucosaminidase and beta-glucuronidase may be present in rat myometrium. Estrogen seemed to labilize the lysosomal membrane of at least the latter of the two proposed populations of myometrial lysosomes.
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PMID:Effect of ovarian hormones on lysosomal acid hydrolase activities in rat myometrium. 55 4

A comparative study was made of the total lysosomal enzyme activity found in homogenates of normal ectocervical squamous epithelium and squamous carcinoma of this epithelium. The activities of acid phosphatase, beta-glucuronidase, cathepsin D and acid ribonuclease were higher in carcinoma tissue than in normal tissue. The most important observation made was with regard to the distribution of enzyme activity in homogenates. In carcinoma homogenates most of the enzyme activity was detected in the lysosomal fractions, whereas in controls the activity was predominantly found in the cytosol fractions. No histochemical and electron microscopical techniques were used in this study. Because it was possible to sediment the enzyme activity and to demonstrate latency, these can be referred to as lysosomal enzymes with certainty.
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PMID:[A comparism between lysosomal enzyme activity in normal ectocervical squamous epithelium and squamous carcinoma of the ectocervix]. 56 9

Activity of arylsulphatase, beta-glucuronidase, cathepsin D, and acid phosphatase in the homogenates of melanotic and amelanotic melanoma was determined. The activity of these enzymes is higher in melanotic than in amelanotic melanoma. Respective values for melanotic and amelanotic tumours are: arylsulphatase 10,78 +/- 3,20, and 1,45 +/- 0,66 micron 4-nitrocatechole/mg protein/hr; beta-glucuronidase 11,10 +/- 1,40, and 9,98 +/- 1,35 micron phenolphthalein/mg protein/hr; cathepsin D 4,24 +/- 1,37, and 3,26 +/- 0,73 micron tyrosine/mg protein/hr; acid phosphatase 230 +/- 22, and 180 +/- 25 micron p-nitrophenol/mg protein/hr. These differences are statistically significant. The increased activity of the lysosomal enzymes in melantoic melanoma probably depends on the occurrence of an higher number of lysosomes in tissues containing melanins.
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PMID:Activity of some lysosomal hydrolases in the homogenates of transplantable melanotic and amelanotic melanoma in golden hamster (Mesocricetus auratus, Waterhouse). 68 81

Occlusion of the circumflex coronary artery induced a profound redistribution in ischemic rabbit myocardium of several lysosomal acid hydrolases, including cathepsin D, B-acetylglycosaminidase, and acid phosphatase. 30-45 min after ligation non-sedimentable cathepsin D activity rose from 36% of the total activity to 42-48%, and in immunohistochemical preparations cathepsin D appeared to have diffused from lysosomes into the cytosol of injured cells. A pharmacologic dose of methylprednisolone (50mg/kg) significantly delayed the subcellular redistribution of cathepsin D and the other hydrolases in ischemic heart. Thus, in treated hearts the nonsedimentable activity of cathepsin D rose to only 38% after 30 min of ischemia and 42% after 45 min (P is less than 0.05 compared to untreated ischemia at each time). Similarly, unlike untreated hearts, noevidence of enzyme diffusion from lysosomes could be demonstrated immunohistochemically in corticosteroid-treated ischemic hearts for over 45 min. After 1-2 h of ischemia, however, steroid-protected myocytes deteriorated and the biochemical activity and anatomical distribution of cathepsin D were indistinguishable from untreated ischemic hearts. This study demonstrates that corticosteroid pretreatment does not prevent alterations in cardiac lysosomes during severe ischemia indefinitely, but does delay their development significantly.
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PMID:Influence of methylprednisolone of the sequential redistribution of cathepsin D and other lysosomal enzymes during myocardial ischemia in rabbits. 70 78

Hearts of late fetal mice were maintained in organ culture in the presence of 30-100 mM sucrose or mannitol. Activities of several lysosomal enzymes (cathepsin D, beta-acetylglucosaminidase, acid phosphatase) were increased by up to 30% after 18-24 hours and by up to 50% after 48-72 hours, as compared to enzyme activities in litter-matched hearts maintained in control medium or medium supplemented with equimolar urea. Simultaneously, the ratio of nonsedimentable to sedimentable enzyme activity was significantly increased, suggesting increased lysosomal fragility. Light and electron microsopic examination of the hearts revealed marked vacuolization in myocytic, interstitial, and endothelial cells. The vacuoles were limited by single membranes, often contained particulate or amorphous cellular debris resulting from autophagocytosis, and in cytochemical preparations frequently exhibited an electron-dense reaction product indicative of acid phosphatase activity. Hydrocortisone failed to prevent the marked lysosomal activation induced by the sugars. In conclusion, prolonged exposure to nonmetabolizable sugars induces severe lysosomal derangements with prominent autophagy, in fetal mouse heart maintained in organ culture.
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PMID:Cardiac lysosomal derangements in mouse heart after long-term exposure to nonmetabolizable sugars. 83 Apr 35

The activity of four lysosomal enzymes (hyaluronidase, beta-N-acetylglucosaminidase, acid phosphatase, and cathepsin D) was studied in aqueous extracts of the light mitochondrial fraction of regenerating male rat liver. This tissue was chosen as a model for normal cell division in vivo. In the first wave of division, 40 to 50% of the cells divide synchronously. Activities were measured at 0, 9, 18 (end of G1 phase), 24 (S phase), and 30 hr (mitosis) and during regeneration, 4 and 11 days after partial hepatectomy. Activities were related to fresh tissue weight, to cellular DNA, and to protein content of the extracts. At 9 hr, there was an important increase in hyaluronidase and cathespin D activities (these two enzymes act upon macromolecules); beta-N-acetylglucosaminidase and acid phosphatase activities were only slightly increased. At the end of the G1 phase, 40 to 50% of the activity of all four enzymes was lost, which might indicate complete loss of activity in cells undergoing division. This depletion persisted until mitosis was complete. Four days later, there was a slow restoration of enzyme activities; after 11 days, hyaluronidase and cathepsin D exhibited about 80% of their initial activity, whereas beta-N-acetylglucosaminidase and acid phosphatase only regained about 50%. These results show that the lysosomal system perhaps plays some role in cell division.
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PMID:Lysosomal enzyme activities in the regenerating rat liver. 83 61

Prolonged starvation is known to induce significant alterations in several cardiac lysosomal enzymes, particularly the acid proteinase cathepsin D. To determine what specific factors might mediate these changes, fetal mouse hearts in organ culture were maintained in media designed to simulate selected hormonal or nutritional substrate changes that accompany starvation. Reduced concentrations of glucose caused an increase in the activity of beta-acetylglucosaminidase but had no effect on cathepsin D or acid phosphatase activites (i.e., effects opposite from those of starvation). Also, high concentrations of free fatty acid, acetoacetate, and beta-OH-butyrate induced an increase in cathepsin D (+18%) and a simultaneous decrease in glucosaminidase (-19%), with little change in acid phosphatase. Furthermore, glucagon had no effect on any of the enzymes, whereas growth hormone caused a small (6%) increase in cathepsin D activity. In addition, insulin deprivation caused significant increases (7-25%) in the activities of all three enzymes. Insulin deprivation and excess ketones, but not the other interventions, increased the proportion of enzyme activity which was nonsedimentable. These results suggest the possibility that lysosomal alterations during starvation may be related in part to prolonged insulin deficiency and exposure to high concentrations of ketones and free fatty acids.
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PMID:Hormonal and nutritional substrate control of cardiac lysosomal enzyme activities. 95 75

Gel-forming mucosal glycoproteins strongly interfere with standard methods of cell fractionation. Thus, acid hydrolase-bound particles imbedded in the gel, sediment on centrifugation, in the nuclear fraction of homogenates of canine antral mucosa. These particles can be cleared by direct solubilization of the gel; however, the viscosity of the solution obtained prevents sedimentation of some of the latent hydrolases, even at very high speeds. The use of a new step-wise scheme of centrifugation and dilution successfully isolates lysosomal particles containing acid hydrolases from mucin-rich mucosa. All of the enzymes investigated, including acid phosphatase, cathepsin D, alpha- and beta-galactosidase, beta-B-acetylhexosaminidases, but with the exception of alpha-fucosidase, were found to be particle bound, exhibiting high degrees of latency. However, active mucosal particles are polydisperase in size and density, sedimenting under different centrifugal forces.
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PMID:Establishment of the integrity of lysosomes in a glycoprotein-rich matrix. Distribution pattern of seven lysosomal enzymes in gastric mucosa. 97 20


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