Figure 7. Time relationship for simultaneously measured relaxations and increases in NO.

Averaged relaxations (○) and increases in NO (□) at various times after the addition of 10 μM SNAP (A), 10 μM SIN-1 (B), and 50 nmol l⁻¹ min⁻¹ infused NO (C) in rat superior mesenteric arteries contracted with 0.5 μM noradrenaline (NA). The NO infusion (C) was stopped after 10 min (arrow), and this was followed by a fall in NO concentration and recovery of the noradrenaline-induced contraction. NO concentrations are given as increases above the level in the absence of acetylcholine. Each point represents the mean ±s.e.m. of 4-6 preparations.