Figure 4. Individual responses of one subject to protocol 2.

After stellate ganglion block, handgripping to fatigue caused forearm blood flow to increase 2.5-fold. Administration of propranolol via a brachial artery catheter had no effect on baseline blood flow after stellate block but blunted the increase in flow during handgripping and post-exercise ischaemia (PEI). L-NMMA given prior to the third bout of exercise caused a marked reduction in resting forearm blood flow and eliminated any changes in forearm blood flow during the final bout of handgripping.