Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Latencies and phosphomannosyl-enzyme receptors of lysosomal enzymes were studied in the skeletal muscles of NMRI mice during the appearance (0-1 days) and the repair (3-9 days) of muscle fiber injuries after a single bout of prolonged running (9 hr, 13.5 m/min). The unsedimentable, releasable, and bound activities of arylsulfatase, beta-N-acetylglucosaminidase, beta-D-glucuronidase, cathepsin C, and ribonuclease as well as the content and occupancy of phosphomannosyl-enzyme receptors of lysosomal enzymes were assayed. The distribution of enzyme activities in different fractions as well as the changes after exertion greatly varied between different lysosomal enzymes. In general, the total activities and also the distribution of enzyme activities in different fractions were unaffected 1 hr after exertion, but on the day after exertion small increases were observed in the free and releasable activities. The highest enzyme activities both in the homogenate and in different fractions were recorded 3 days after exertion, after which the activities slowly decreased. The increases of enzyme activities were higher in the free and releasable fractions than in the homogenate but the changes in the proportional distributions of lysosomal enzyme activities between different fractions were minor. The present study also showed the presence of phosphomannosyl-enzyme receptors of lysosomal enzymes in the membranes of skeletal muscles. The total content of phosphomannosyl-enzyme receptors was unchanged 0-3 days after exertion but a small increase occurred 5-8 days after exertion. Instead, the occupancy of these lysosomal receptors with endogenous enzymes was significantly increased 1-5 days after exertion and decreased later to the control level.
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PMID:Latencies and phosphomannosyl-enzyme receptors of lysosomal enzymes during the appearance and repair of exercise injuries in mouse skeletal muscles. 609 63

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

Eosinophils were separated from other types of cells in horse blood or rat peritoneal fluid by centrifugation in concentrated albumin solutions. Eosinophils did not appear to be damaged by this separation procedure. A technique was also devised for isolation of cytoplasmic granules from eosinophils, thus allowing studies on enzyme content of the granules. Granules from both horse and rat eosinophils contained a number of hydrolytic enzymes, similar in variety and in concentration to those previously found in granules of rabbit polymorphonuclear leucocytes. Eosinophil granules differed from those of the rabbit granulocyte in their high content of peroxidase and the absence of lysozyme and phagocytin. On disruption of eosinophil granules by repeated freezing and thawing in saline, cathepsin, ribonuclease, arylsulfatase and beta glucuronidase were released into solution, but phosphatases were partially and peroxidase completely bound to the insoluble granule residue. Peroxidase could be extracted from the granule residue with weak acid. Eosinophil granules thus are lysosome-like structures.
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PMID:ISOLATION OF GRANULES FROM EOSINOPHIL LEUCOCYTES AND STUDY OF THEIR ENZYME CONTENT. 1407 91