NOS1 and Duchenne muscular dystrophy: Vascular dysfunction has been implicated in muscle damage in canine model of DMD (Kodippili et al., 2021) and in human DMD (Thomas et al., 1998), and our analysis of BMD mice also suggests that the reduction of type IIa fibers may be influenced by vascular dysfunction with reduced sarcolemmal nNOS as well as fragility and delayed recovery.