title: Ca2+-activated protease in denervated rat skeletal muscle measured by an immunoassay.
abstract: Right hind leg muscles of adult male rats were denervated by transecting the sciatic nerve, while muscles of the left leg served as a control. On days 4, 9, and 18 after denervation, the rats were killed and the extensor digitorum longus and soleus muscles removed. Extracts were prepared which contained the Ca2+-activated protease. The molecular weight of the protease in the extracts, measured immunologically on Western blots of SDS-polyacrylamide gels, was identical to that of purified standard protease and was unaffected by denervation. The amount of protease in each extract was measured by a solid phase immunoassay using monospecific IgG labeled with 125I, and the results were expressed as units of protease activity per milligram noncollagen protein. There were increases of 40 to 80% in the mean values obtained for both denervated muscles compared with controls. Because the protease is probably localized on the cell membrane, these modest increases are likely to be a consequence of a generalized over-development of muscle membranes which follows denervation.
mesh_terms: D000818:Animals; D002154:Calpain; D010450:Endopeptidases / Q000032:analysis*; D005260:Female; D007118:Immunoassay; D008297:Male; D009121:Muscle Denervation; D009132:Muscles / Q000201:enzymology* / Q000294:innervation; D011817:Rabbits; D051381:Rats
chemical_list: D010450:Endopeptidases; D002154:Calpain