*4.2. Muscle Regeneration*

In the present study, increase in muscle weight and fiber CSA in CTX-injected TA muscle was observed during a 2-week experimental period. In addition, the population of Pax7-positive nuclei was increased by CTX injection. These phenomena are consistent with the previously reported data in mice [23]. Larger muscle mass and Pax7-positive nuclei population were also observed in lactate-administered mouse, which suggests that lactate stimulates the regenerative potential of injured skeletal muscle by activating muscle satellite cells.
