Fig. 5. Time course of nitric oxide concentration in the coronary effluent for 30 min after the onset of reperfusion. (  A ) Representative time course of the measured current. (  B ) Time course of nitric oxide concentration measured corresponding to the current in five groups (n = 4 for each group). *  P < 0.05: POST  versus control (CTL), CTL + aprotinin (APRO), postconditioning (POST) + APRO, and POST +  N -nitro-l-arginine methylester (l-NAME). †  P < 0.05: POST + l-NAME  versus CTL, CTL + APRO, POST, and POST + APRO.