Figure 7.

Protein levels of key molecules related to the SNARE-SM ACh release complex of young and ageing EDL muscles. (A), Western blot analysis of different protein kinases targets and their phosphorylated forms. Quantification analysis shows a decrease in phosphorylated Munc18-1 and an increase in Munc18-1 protein levels in ageing muscles. The SNAP-25 protein level does not change as the PKA-dependent pSNAP-25 (T138) does. However, the cPKCβI- and nPKCε-dependent pSNAP-25 (S187) are greatly reduced in ageing. (B), The distribution of the protein kinases targets between the membrane and cytosol fractions shows no differences between young and ageing muscles. Data are represented as means ± SD. Statistical significance was determined using the Mann–Whitney test (* p value < 0.05).