Figure 5.

Correspondence between skeletal muscle nNOS and blunted vasoconstriction in exercising forearm. (a) Immunoblots of skeletal muscle biopsy samples from children with DMD, SMA, PM, or LGMD. Blots were probed for nNOS, eNOS, and iNOS (not detected in any sample). +, positive control. (b) Sympathetic vasoconstriction, as assessed by LBNP-induced decreases in muscle oxygenation, in resting and exercising forearm measured in the same children whose biopsies were analyzed in a. Vasoconstrictor responses were not attenuated in exercising forearm in children with DMD or SMA, but were greatly attenuated in those with PM or LGMD.