Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activities of acid proteolytic enzymes were assayed in the liver and muscular tissues of mice (Mus musculus) 1, 6 and 24 hr after the administration of a protease inhibitor leupeptin (i.p., 15.5 mg/kg body wt). Leupeptin administration induced a strong inhibition of cathepsin B and a moderate inhibition of cathepsin C and acid autolytic rate in mouse liver 1 hr after injection. Thereafter the inhibition reduced and disappeared during 24 hr. The activity of cathepsin D was increased in liver 6 and 24 hr after injection. The activity of beta-glucuronidase was not affected by the leupeptin treatment. The administration of leupeptin did not affect the rate of acid autolysis and the activities of cathepsin C and D in cardiac and skeletal muscles. A slight increase in cathepsin B activity was observed 1 hr after leupeptin treatment in calf muscles. The cause of both tissue and enzyme specific changes after leupeptin treatment is discussed.
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PMID:Acid proteolytic activities in mouse liver and muscle tissues after treatment with protease inhibitor leupeptin. 614 85

Leupeptin, antipain, tosyl-lysylchloromethane (Tos-Lys-CH2Cl) and benzyloxy-carbonylphenylalanylalanyldiazomethane (Z-Phe-Ala-CHN2) inhibit reversibly the resorption induced by parathyroid hormone or heparin in cultured mouse bones. Leupeptin and antipain do not affect collagenase production and activity or the enhanced secretion of beta-glucuronidase induced by the bone-resorbing agents. They might thus act by a direct (extracellular?) inhibition of lysosomal thiol proteinases.
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PMID:Inhibition of bone resorption in culture by inhibitors of thiol proteinases. 627 2

Leupeptin, a nontoxic thiol protease inhibitor, has been proposed to have therapeutic use in hereditary muscular dystrophies. The purpose of this study was to characterize the in vivo changes in proteolytic activity of skeletal muscles induced by the repeated administration of leupeptin. Further, whether the modulation of proteolytic capacity by leupeptin affects the repair process of muscle injuries caused by heavy exercise was studied. Leupeptin was administered in mice intraperitoneally at a dose level of 15.5 mg/kg twice a day for 9 days. Leupeptin, known to be an inhibitor of cathepsin B both in vitro and after a single injection in vivo, paradoxically induced an increase of cathepsin B activity in mouse skeletal muscles after repeated administration. In addition, leupeptin administration for 9 days increased the activities of cathepsins C and D, as well as the rate of acid autolysis. The activity of beta-glucuronidase also increased, while those of arylsulfatase, ribonuclease, and alkaline protease were unaffected. No histopathologic changes were observed. At the low dosage used, leupeptin had no effect on the repair process of skeletal muscle after exercise injuries, although several proteolytic processes occur during the regeneration. It is suggested that the increase of acid protease activities in skeletal muscles is an adaptive response to the administration of the proteolytic inhibitor leupeptin and that leupeptin can be administered without prevention or delay of regenerative processes after the onset of myopathic changes.
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PMID:Effects of the protease inhibitor leupeptin on proteolytic activities and regeneration of mouse skeletal muscles after exercise injuries. 638 26

Leupeptin is an established, reversible inhibitor of cathepsin B, a lysosomal cysteine proteinase. Yet, in rat fibroblasts as well as in foetal mouse calvaria, we observed an increase of the activity of cathepsin B in homogenates of cells and tissue harvested after culture in the presence of leupeptin. This effect was also seen for other lysosomal hydrolases, namely sphingomyelinase, N-acetyl-beta-glucosaminidase, arylsulphatase A and phospholipase A1 in fibroblasts, and beta-glucuronidase in mouse calvaria. In calvaria, antipain, another reversible cysteine proteinase inhibitor, caused a similar effect, whereas E-64, an irreversible inhibitor, was consistently inhibitory of the cathepsin B activity; yet it also caused an increase of beta-glucuronidase activity. The effect of leupeptin in fibroblasts was dose and time-dependent, required the continuous presence of the inhibitor, and was not dependent from protein synthesis. Actually, addition of cycloheximide caused a severe loss of activity of cathepsin B and of sphingomyelinase. In the presence of both cycloheximide and leupeptin, however, these two activities were retained to a value corresponding to that found in excess in cells cultivated with leupeptin alone. The data therefore suggests that leupeptin exerts the effects described in this paper by preventing the degradation of cathepsin B, sphingomyelinase and probably several other lysosomal hydrolases by cysteine proteinases. We therefore propose that cysteine proteinases play a key role in the control of the steady-state levels of these enzymes in normal conditions.
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PMID:Increased activities of cathepsin B and other lysosomal hydrolases in fibroblasts and bone tissue cultured in the presence of cysteine proteinases inhibitors. 793 17