Fig. 4.

Timing of flow restoration. In protocol 1 (A), the time to reach steady-state blood flow during balloon inflation under nitric oxide synthase inhibition (l-NMMA) was increased. The combined inhibition of nitric oxide synthase and adenosine (l-NMMA-aminophylline) did not delay the restoration of flow beyond l-NMMA alone. In protocol 2 (B), the restoration of flow was not delayed during adenosine receptor inhibition (aminophylline) alone. Combined aminophylline-l-NMMA increased the time to reach steady-state blood flow compared with the no-drug and aminophylline-alone trials. *P < 0.05 vs. control (no drug); †P < 0.05 vs. aminophylline alone.