Age-Related Maintenance of the Autophagy-Lysosomal System Is Dependent on Skeletal Muscle Type

Figure 4

Fast-twitch muscle displays a higher number of lysosomes but lower lysosomal activity. (a) Immunoblot of LAMP1 protein in both young and old SOL and EDL muscles. Blots with the respective representative densitometric quantifications are normalized with Ponceau S staining (results in percentage). Statistical significance was given as follows: (Mann-Whitney test). (b) Lysosomal degradation after 2 h kinetics. Quantification from the kinetic release of AMC cleaved by cathepsins B and L from young and old muscles. Values expressed in nanomoles of product formed/minutemilligram of protein. Muscle of 5 mice were used from each group. Statistical significance was given as follows (Student’s -test). For (a) and (b), values are presented as

(a)

(b)