Objective: In response to both endogenous and exogenous stimuli, mammalian mitochondria undergo dynamic structural remodeling via fusion and fission events (mitochondrial dynamics), which support biogenesis, maintain functional integrity, and assist in the removal of dysfunctional organelles. However, whether the responses to high-fat diet change mitochondrial dynamics in both slow- and fast-twitch muscles remains unknown. The purpose of this study was to investigate the effects of a high-fat diet on the expression of mitochondrial fission-related protein Drp1 in both slow- and fast-twitch muscles.

Materials and Methods: Female Sprague-Dawley rats (4-weeks old) were assigned to either a high-fat diet or a sedentary control environment for 8 weeks. After 8 weeks of high-fat diet, the animals were sacrificed, and red and white portions of the gastrocnemius muscle were dissected. These muscles were prepared for western blotting analysis to quantify the protein level of Drp1, which regulates mitochondrial fission.

Results: After 8 weeks of feeding with high-fat diet, there were no changes in the levels of Drp1 in either slow- or fast-twitch muscles.

Conclusions: In conclusion, high-fat diet did not affect the protein level of Drp1 in the slow- or fast-twitch muscles.