Transplantation of muscle-derived stem cells into the corpus avernosum restores erectile function in a rat model of cavernous nerve injury

Purpose: Muscle-derived stem cells (MDSCs) harvested from skeletal muscles have the advantage of providing easier access and do not pose the immunogenic risks of embryonic stem cells. We investigated the effect of intracavernosal transplantation of MDSCs on erectile function in rats with bilateral cavernous nerve injury. Materials and Methods: Adult male white rats underwent experimentation in 3 groups: group I, sham operation; group II, bilateral cavernous nerve injury; group III, bilateral cavernous nerve injury with MDSC injection. MDSCs were harvested from the femoral muscle of rats and were then injected into the cavernosum. Survival of MDSCs and measurement of erectile function was studied after 4 weeks. We checked the intracavernosal pressure (ICP) and obtained penile tissue. The expression of cyclic guanosine monophosphate (cGMP) was analyzed. Results: Four weeks after transplantation, PKH-26-labeled MDSCs were identified in the cavernosal tissues of group III. Peak ICP and the drop rate of group II were 52±8.7 mmHg and 34±6.5 mmHg/min, respectively, whereas peak ICP and the drop rate of group III were 97±15.6 mmHg and 17±4.9 mmHg/min, respectively, showing that erectile function improved after MDSC transplantation (p<0.05). The expression of cGMP was significantly lower in group II (21.9±5.8 fmol/well) than in group I and group III (70.2±10.3 and 58.9±10.5 fmol/well, respectively). Conclusions: In a cavernous nerve injury rat model, intracavernosal transplantation of MDSCs showed acceptable survival of MDSCs as well as improvement of erectile function.