Fig. 1.
Schematic of study protocols. Forearm blood flow (FBF) was measured by using venous occlusion plethysmography. A: effect of low body negative pressure (LBNP) on FBF was measured during infusion of NG-monomethyl-l-arginine (l-NMMA; 2 μmol/min) and vehicle, and S-methyl-l-thiocitrulline (SMTC; 0.2 μmol/min) and vehicle. B: effect of LBNP on FBF was measured during infusion of propranolol and vehicle. C: effect of low- and high-intensity hand-grip exercise on FBF was measured in the presence of l-NMMA and vehicle and also with vehicle throughout. D: effect of simultaneous LBNP with low- and high-intensity exercise on FBF was measured in the presence of l-NMMA, SMTC, and saline control in a cross-over study.