Duchenne muscular dystrophy is a lethal neuromuscular disease that currently has no effective therapy. Transgenic overexpression of the ␣7 integrin in mdx/ utrn ؊/؊ mice, a model of Duchenne muscular dystrophy ameliorates the disease. We have isolated and used ␣7 ؉/؊ muscle cells expressing -galactosidase, driven by the endogenous ␣7 promoter, to identify compounds that increase ␣7 integrin levels. Valproic acid (VPA) was found to enhance ␣7 integrin levels, induce muscle hypertrophy, and inhibit apoptosis in myotubes by activating the Akt/mTOR/p70S6K pathway. This activation of the Akt pathway occurs within 1 hour of treatment and is mediated by phosphatidylinositol 3-OH kinase. To evaluate the potential use of VPA to treat muscular dystrophy, mdx/utrn ؊/؊ mice were injected with the drug. Treatment with VPA lowered collagen content and fibrosis, and decreased hind limb contractures. VPA-treated mice also had increased sarcolemmal integrity and decreased damage , decreased CD8-positive inflammatory cells , and higher levels of activated Akt in their muscles. Thus , VPA has important biological effects that may be applicable for the treatment of muscular dystrophy.