Figure 2 Putative mechanisms of action of shockwave therapy for ED Figure 2 | Putative mechanisms of action of shockwave therapy for ED. Shockwaves form microbubbles (A) in the vasculature and tissue that collapse (B) and cause disruption of the endothelium (C). Endothelial disruption might activate resident stem cells (D) and result in chemokine production with attraction of (endothelial) progenitor cells (E) and release of VEGF (F); these factors combine to initiate neoangiogenesis (G). In addition, microbubble collapse induces shear stress and might simulate endothelial NO production (H). Furthermore, shockwave therapy might also enhance Schwann-cell-mediated nitrergic-nerve repair after injury (I). Fode, M. et al. (2017) Low-intensity shockwave therapy for erectile dysfunction: is the evidence strong enough? Nat. Rev. Urol. doi:10.1038/nrurol.2017.119