Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Structural and functional changes in the dog liver and regional lymph nodes lysosomes were studied during toxic hepatitis induced by CCl4 administration (single and repeated). Total activity of lysosomal enzymes (acid RNA-ase and beta-galactosidase) was higher in the regional lymph nodes than in the liver, reflecting the barrier, protective function of the organ. During acute toxic hepatitis the specific activities of acid RNA-ase and cathepsin D displayed a sharp rise. No normalization of the indices under study occurred during the observation period (from 8 to 30 days). At the same time there was a rise of the regional lymph node weight and an elevation of the relative macrophage and neutrophil content in the sinuses. The increased activity of the lysosome enzymes in the regional lymph nodes in injury of the liver was connected with greater functional load on the lymph nodes effecting hydrolysis of biopolymeres which penetrated into the regional lymphatic node with the lymph.
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PMID:[Structuro-functional changes in dog liver and regional lymph node lysosomes in toxic hepatitis]. 70 70

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

Parenchymal and nonparenchymal cells were isolated from the livers of female BN/BiRij rats, aged 3, 12, 24 and 30-35 months, by means of enzymatic techniques. About 70% of the cells in the nonparenchymal cell suspensions were endothelial cells and 25% were Kupffer cells. More than 90% of the isolated parenchymal, Kupffer and endothelial cells were viable as judged by trypan blue exclusion and ultrastructural appearance. The age-related changes in the specific activities of the lysosomal enzymes acid phosphatase, beta-galactosidase, cathepsin D and arylsulphatase B in parenchymal and nonparenchymal cells showed no correlated behavior. The most prominent change was observed for the cathepsin D activity in parenchymal cells, which nearly triples during the lifespan of the rat. A comparison of the activities obtained with homogenates of the whole liver and with parenchymal and nonparenchymal cells revealed that aging changes in lysosomal enzyme activities in homogenates should be carefully interpreted, since opposite patterns of change were often observed in the activities in parenchymal cells and in nonparenchymal cells.
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PMID:Lysosomal enzyme activities in parenchymal and nonparenchymal liver cells isolated from young, adult and old rats. 99 58

The nonselective beta-blocker propranolol and the selective beta 1-adrenoblocker flusoxolol were tested for their effects on the activities of acid phosphatase, acid DNAase, cathepsin D, beta-glucosidase and beta-galactosidase in intact rat ventricular myocardial homogenates. The two drugs were found to have the most noticeable effect on the activity of three enzymes under study: acid phosphatase, beta-glucosidase and beta-galactosidase. They were able to stabilize lysosomal membranes during long-term homogenate preincubation at 37 degrees S. It is suggested that the mechanism of action of the drugs on intact rat ventricular myocardial lysosomes under the conditions of the study involves the binding of both propranolol and flusoxolol to beta-adrenoceptors on the lysosomes.
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PMID:[The effect of propranolol and flusoxolol on the lysosomal enzyme activity of the rat ventricular myocardium]. 136 45

The influence of cardioselective beta-blockers, practolol and atenolol, on acid phosphatase, acid deoxyribonuclease, cathepsin D, beta-glucosidase and beta-galactosidase activities was studied in homogenates of intact rat ventricular myocardium. In the presence of drugs (1 x 10(-9)-1 x 10(-5) M) the activities of acid phosphatase, cathepsin D, beta-glucosidase and beta-galactosidase tended to diminish but the activity of acid deoxyribonuclease tended to increase. Some differences in the influence of drugs on the enzyme activities were removed by prolongation of preincubation of homogenates with drugs. It is supposed that the mechanism of influence of beta-blockers on lysosomes of the intact rat ventricular myocardium in conditions of this study includes the specific drug binding to beta-adrenergic receptors situated on lysosomes.
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PMID:[The effect of practolol and atenolol on the lysosomal enzyme activity of the ventricular myocardium of rats]. 166 75

1. Chloroquine accumulation in rat liver after a single and repeated drug administration and lysosomal changes resembling some symptoms of lysosomal storage diseases were observed. 2. Repeated chloroquine treatment of rats resulted in increased activity of liver lysosomal enzymes acid phosphatase and beta-galactosidase and a significant enhancement of the activities of cathepsin D and cysteine proteinases were found. 3. No changes in the activity of liver macrophages (as assessed by the colloidal carbon clearance test) or in fluid-phase endocytosis of the marker 125I-polyvinyl-pyrrolidone by hepatocytes in vivo were found.
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PMID:Effects of chloroquine on lysosomes and endocytosis by liver cells in vivo. 184 18

Unicameral bone cyst fluid possesses N-acetyl-beta-D-glucosaminidase, beta-glucuronidase, PZ-peptidase, cathepsin D, acid phosphatase, N-acetyl-beta-D galactosaminidase, and beta-galactosidase activities. The activities of lysosomal enzymes in the cyst fluid are, as a rule, higher than in the serum, whereas the total protein content is lower. The content of collagen degradation products in the cyst fluid is higher compared to the serum. In bone cavity wall tissues, the collagen content is decreased. Adenosine 3':5'-cyclic phosphate and cyclic guanosine 3,5'-monophosphate accumulate in the cyst cavity. However, in some cases, there is no correlation among the activities of lysosomal enzymes in the cyst fluid, blood serum, and cyst wall tissues. The ratios of lysosomal enzyme activities in the cyst fluid differ from those in the cyst wall tissues, cultured skin fibroblasts, and blood polymorphonuclear leucocytes. The lack of coincidence of enzymatic spectra of the cyst fluid, wall tissues, and serum is suggestive of the diversity of ways of lysosomal enzyme enter the cyst cavity, i.e., blood, cyst fluid cells, and cyst cavity walls. The cysts with different locations (i.e., active and latent cysts) have similar lysosomal lytic potentials. The presence in the cyst cavity of extracellular lysosomal enzymes and collagen degradation products testifies to the permanent corrosion of the cyst cavity walls from the inside as well as to the increase in the osmotic pressure of the cyst fluid. Lysosome destruction should be regarded as an important pathogenetic factor that requires surgical or pharmacologic correction or both in the course of bone cyst management.
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PMID:The role of lysosomes in the pathogenesis of unicameral bone cysts. 185 Mar 36

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase is a key regulatory enzyme of cholesterol biosynthesis and is located in the endoplasmic reticulum (ER). A fusion protein, HMGal, consisting of the membrane domain of HMG-CoA reductase fused to Escherichia coli beta-galactosidase and expressed in Chinese hamster ovary (CHO) cells from the SV40 promoter, was previously constructed and was found to respond to regulatory signals for degradation in a similar fashion to the intact HMG-CoA reductase. Degradation of both HMG-CoA reductase and HMGal in CHO cells was enhanced by addition of mevalonate or low density lipoprotein (LDL). In this report we show that 2 cysteine protease inhibitors, N-acetyl-leucyl-leucyl-norleucinal (ALLN) and N-acetyl-leucyl-leucyl-methioninal (ALLM), completely inhibit the mevalonate- or LDL-accelerated degradation of HMG-CoA reductase and HMGal and also block the basal degradation of these enzymes. It has been shown that in vitro these protease inhibitors inhibit the activities of Ca(2+)-dependent neutral proteases as well as lysosomal proteases, including cathepsin L, cathepsin b, and cathepsin D. However, the mevalonate-accelerated degradation of HMG-CoA reductase and HMGal is not affected by lysosomotropic agents, suggesting that the site of action of these inhibitor peptides in preventing the degradation is not the cathepsins. In brefeldin A-treated cells, where protein export from the ER is blocked, ALLN is still effective in inhibiting the degradation of HMG-CoA reductase and HMGal. These results indicate the involvement of non-lysosomal Ca(2+)-dependent proteases in the basal and the accelerated degradation of HMG-CoA reductase and HMGal. Enzymatic assays in vitro and immunoblot analyses have revealed calpain- and calpastatin-like proteins in CHO cells. The activities and the amount of these proteins do not change under conditions of enhanced degradation, indicating that the levels of these proteins are not subject to mevalonate regulation.
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PMID:Inhibition of degradation of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in vivo by cysteine protease inhibitors. 190 66

The changes in the activities of certain lysosomal hydrolases, viz., beta-glucuronidase, beta-N-acetylglucosaminidase, beta-galactosidase, beta-glucosidase, alpha-glucosidase, alpha-galactosidase, alpha-mannosidase, cathepsin B, cathepsin D, and collagenolytic cathepsin, in serum and heart of rats subject to myocardial infarction with isoproterenol, were studied during the periods of peak infarction and recovery. The activities of all the enzymes assayed exhibited a significant increase both in serum and in heart at peak infarction stage and these levels returned to normal during the stage of recovery and repair. The infiltration of inflammatory cells at the infarct regions and the altered lysosomal fragility are probably responsible for the increased activity of the enzymes studied. This may also bring about the catabolism of connective tissue constituents as reported in literature.
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PMID:Influence of isoproterenol-induced myocardial infarction on certain glycohydrolases and cathepsins in rats. 201 10

The synthesis and secretion of pro-cathepsin D is increased by estrogens in MCF7 cells. We quantified the effect of estradiol on other lysosomal enzymes in order to investigate the mechanism of this hypersecretion. Precursors of beta-hexosaminidase, cathepsin B and beta-galactosidase, which are routed to lysosomes via the mannose-6-phosphate (Man-6-P) receptor, were secreted in much lower amounts than pro-cathepsin D, but their secretion was also increased by estradiol. The activity of acid phosphatase, which is routed to lysosomes via a different transmembrane mechanism, was not altered by estradiol. While estradiol stimulated gene expression of pro-cathepsin D, it had no effect on that of pro-cathepsin B. We conclude that estradiol stimulates the secretion of several lysosomal pro-enzymes in MCF7 cells, suggesting that a general mechanism is responsible for this derouting rather than a specific alteration of cathepsin D structure.
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PMID:Estradiol increases the secretion by MCF7 cells of several lysosomal pro-enzymes. 222 57


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