Enzymatic changes in dystrophic mice and their age dependency.
The activities of 14 different aminopeptidases, 5 endopeptidases, 4 glycosidases, phosphatase, esterase, and ribonuclease (RNase) were measured in the muscle and bone of 12 normal controls and 12 dystrophic mice. In most cases the activity of these enzymes was significantly elevated in the muscle of the dystrophic mice. In the muscle of the controls the activity of aminopeptidase A (AP-A), Leu-AP, Trp-AP, Gly-Pro-AP, and RNase tended to decrease with the increasing age of the animal, whereas that of AP-B and Pro-AP tended to increase. This mode of age-related regression was entirely different in dystrophic muscle. The enzymatic changes in the bone of the dystrophic mice were milder but more or less analogous to those in muscle. These findings should be important in further elucidating the mode of protein degradation in dystrophic muscle and in aiding in the selection of appropriate therapeutic agents including the low-molecular-weight inhibitors.
D000375:Aging; D000818:Animals; D001842:Bone and Bones / Q000201:enzymology; D051379:Mice; D008810:Mice, Inbred C57BL; D009132:Muscles / Q000201:enzymology; D009137:Muscular Dystrophy, Animal / Q000201:enzymology*