Fig. 1.
Schematic diagram of experimental protocol. Subjects completed 3 exercise trials. Each exercise trial consisted of baseline, exercise (control), exercise during inflation, exercise after deflation, and recovery measurements (3 min each). Exercise trials were performed during control (no drug), NG-monomethyl-l-arginine (l-NMMA; protocol 1), adenosine receptor inhibition (aminophylline; protocol 2), and combined l-NMMA-aminophylline infusions (both protocols). Each trial was separated by at least 20 min of rest to allow forearm blood flow (FBF) to return to baseline values. Adenosine (ADO) dose-response infusions were performed at the start of the study under control (no drug) conditions and repeated during l-NMMA (protocol 1), aminophylline (protocol 2), and combined l-NMMA-aminophylline (both protocols). MVC, maximal voluntary contraction.