Effect of Porphyromonas gingivalis Infection on PGC‐1α in Skeletal Muscle After Endurance Training In Vivo

Objectives It is well known that Porphyromonas gingivalis , a major pathogen in periodontitis, causes systemic diseases. This study investigated the expression of PGC‐1α (the most important factor in muscle mitochondria synthesis) following endurance training to clarify the relationship between P. gingivalis infection and muscle endurance capacity. Materials and Methods Twenty 8‐week‐old Wistar rats were randomly divided into two groups. One group was intraperitoneally administered sonicated P. gingivalis ( P. g ‐group), and the other group was administered saline (Control‐group). Three weeks after administration, gastrocnemius muscles and blood from both groups were collected 24 h after treadmill exercise. The expressions of PGC‐1α and TNF‐α in gastrocnemius muscle were measured, along with serum antibody titers for IgG, in response to P. gingivalis . Results Serum IgG antibody titers and TNF‐α expression in skeletal muscle were significantly higher in the P. g ‐group than in the Control‐group. PGC‐1α expression was significantly lower in the P. g ‐group than in the Control‐group. A correlation was observed between PGC‐1α and TNF‐α expression. Conclusion Our result suggests that the increase in endurance following training may be suppressed by P. gingivalis infection.