A, representative western blot and densitometry quantification results for phosphor‐S1412‐nNOS (pnNOS), an indicator of contraction‐induced nNOS activation (n = 4 normal dogs). *Significantly different from the remaining three experimental conditions. B and C, representative tracings of mean arterial pressure (MAP) and blood flow (BF) in response to noradrenaline (NE) administration at rest and during contraction in a normal (A) and a DMD (B) dog in the presence of 7‐NI. D and E, percentage decrease in mean vascular conductance (MVC) in response to NE administration at rest and during contraction in normal (n = 8) and DMD (n = 14) dogs in the presence of 7‐NI. F, efficiency of functional sympatholysis in normal (n = 8) and DMD dogs (n = 14) in the presence of 7‐NI. *Significantly different from resting.