Fig. 5.

Vasodilator responses to bolus infusions of acetylcholine (ACh) during saline (control) and l-NMMA administration in young and older adults. A: rapid vasodilator responses (ΔFVC) over 60 cardiac cycles after bolus infusion of ACh. Peak (B) and total (C) vasodilator responses to ACh were attenuated in older adults under control conditions. NO synthase inhibition (l-NMMA) blunted the peak and total vasodilator responses to ACh in young adults (B and C). *P < 0.05 vs. young. †P < 0.05 vs. control.