Our goal was to determine whether periurethral injection of allogenic muscle-derived stem cells (MDSC) could increase the leak point pressure (LPP) in a denervated female rat model of stress urinary incontinence. Cells isolated from the gastrocnemius muscle of normal female rats were purified for a myogenic population by the preplate technique. Three experimental groups were established: a control group (C) had a sham operation without injections; a sciatic nerve transection group (D) had periurethral saline injections; and a sciatic nerve transsection group had periurethral MDSC injections (M). One week following treatment the LPP of groups C, D and M were 25.2+/-1.9 cmH(2)O, 28.6+/-0.8 cmH(2)O and 36.7+/-2.3 cmH(2)O, respectively. At 4 weeks the LPP of groups C, D and M were 25.8+/-2.5 cmH(2)O, 18.6+/-5.2 cmH(2)O and 44.1+/-6.6 cmH(2)O, respectively. Allogenic MDSC significantly improved the LPP in sciatic nerve-transected animals after both 1 and 4 weeks compared to denervated animals injected with saline.