Effect of vitamin E-deficiency on the activity of some lysosomal and non-lysosomal proteases in rabbit muscles

The activity of different cathepsins and neutral proteinases was measured in normal and vitamin E-deficient rabbit muscles using specific substrates. Among the changes of enzyme activities in dystrophy caused by vitamin E-deficiency the increase in the activity of cathepsin B is the most striking. The activity of cathepsin H, both in the fast and slow muscles and that of MMP-ase in the slow muscle remains practically unchanged. Activities of other proteases significantly increase. The change in the activity of proteolytic enzymes in striated muscle of vitamin E-deficient rabbits seems to be selective. As a rule the increase in the activity is higher in fast than in slow muscles.