Skeletal muscle fibre type-dependent effects of atorvastatin on the PI3K/Akt/mTOR signalling pathway and atrophy-related genes in rats

In the absence of overt muscle damage, atorvastatin decreased the P-Akt/Akt ratio in the MG, indicating an increase in inactive Akt. Consistent with the decrease in Akt activation, rpS6 phosphorylation decreased. In SOL, atorvastatin increased the P-Akt/Akt ratio, indicating Akt activation. P-FoxO3a and the P-FoxO3a/FoxO3a ratio increased, suggesting that FoxO3a inactivation occurred. Moreover, in the SOL, atorvastatin did not affect the expression of atrophy-related genes. These findings indicate that atorvastatin has no adverse effect on the Akt pathway in the SOL. Our results showed that the effects of atorvastatin on the Akt signalling pathway and atrophy-related gene expression depend on muscle type.