Two-step mechanism of myofibrillar protein degradation in acute plasmocid-induced muscle necrosis.
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| Abstract |
Acute muscle necrosis was induced in rats by intramuscular injection of plasmocid, a known myotoxic agent. A single injection of 5 mg/ml plasmocid produced massive fiber necrosis with extensive phagocytosis. Plasmocid administration led to a preferential decrease of alpha-actinin with preservation of other structural proteins within 3 h after injection, and large increases (2-7-fold) in the activities of acid hydrolases, cathepsins B and L, cathepsin D and alpha-galactosidase within 48 h after injection. The plasmocid-induced stimulation of alpha-actinin loss seen at 3 h, when no increases of acid hydrolases occurred, could be inhibited by a cysteine protease inhibitor, Ep-475 (E-64-c), and EGTA. On the other hand, increased lysosomal enzyme activity seemed to have a close correlation with the appearance of invading mononuclear cells, probably macrophages, and not muscle lysosomes. These observations suggest that a two step mechanism of protein degradation (nonlysosomal and lysosomal processes) possibly occurs in plasmocid-induced muscle degradation and macrophages can serve as a main endogenous reservoir of proteases in pathological states.
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| Authors | S Ishiura, I Nonaka, H Nakase, A Tada, H Sugita |
| Journal | Biochimica et biophysica acta (Biochim Biophys Acta) Vol. 798 Issue 3 Pg. 333-42 (Apr 24 1984) ISSN: 0006-3002 [Print] Netherlands |
| PMID | 6424726 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't) |
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