Figure 4. Effect of blockade on augmented hyperaemia during hypoxic exercise.

Hypoxic augmentation of forearm blood flow during exercise was calculated for each condition as the difference in absolute FBF between hypoxic exercise (HypEx) and normoxic exercise (NormEx). In Protocol 1, combined inhibition of NO, PGs, Na⁺/K⁺‐ATPase and K_IR channels blunted the hypoxic augmentation by ∼50%. In Protocol 2, combined inhibition of Na⁺/K⁺‐ATPase and K_IR channels did not significantly affect hypoxic augmentation. ^* P < 0.05 vs. control; ^† P < 0.05 vs. zero.