Effects of atorvastatin on autophagy in skeletal muscles of diabetic rats

Atorvastatin is usually used to decrease the amount of fatty substances in individuals with type 2 diabetes mellitus. However, it can cause side-effects, such as breakdown of skeletal muscle tissue. The present study focused on the effects of atorvastatin on autophagy of the skeletal muscles in diabetic rats.

Diabetes in rats in the diabetic (D) and atorvastatin (T) groups was induced using streptozotocin (65 mg/kg, intraperitoneal injection). Next, rats in the T group were treated with atorvastatin (10 mg/kg/day, intragastric administration), whereas rats in the control and D groups were given water. Additionally, the rats in T and D groups were fed a high-fat and high-sugar diet for 10 weeks. Subsequently, the histopathological changes, and expression levels of microtubule-associated protein 1 light chain 3 (LC3)-I/-II and p62 in the skeletal muscle specimens in the three groups were analyzed.

Rats in the T group had reduced lipid droplets, cholesterol and low-density lipoprotein (P < 0.05) levels than those in the D group. Disordered atrophic myocytes, incrassated vascular walls and decreased cross-sectional area of type I fibers were found using hematoxylin-eosin and adenosine triphosphatase staining in the D and T groups. The messenger ribonucleic acid and protein levels of LC3-II and the LC3-II/LC3-I ratio were increased in the T group compared with those in the other groups (P < 0.05), whereas the protein level of p62 showed the opposite trend.

Atorvastatin enhanced the autophagy level of skeletal muscles to decrease lipid deposition, which possibly exacerbated myopathy.