Vasomotor responses to serotonin and sodium nitroprusside. (A) Dilation of coronary arterioles to serotonin was examined before (Control, n = 16) and after treating with PGI2-S inhibitor TPC (100 μM, n = 4), NOS inhibitor L-NAME (10 μM, n = 3), or CRP (7 μg/mL) in the absence (n = 5) and presence of peroxynitrite scavenger urate (100 μM, n = 4). *P < 0.05 vs. Control. (B) Coronary arteriolar dilation to sodium nitroprusside was examined before (Control) and after incubation with CRP (7 μg/mL, n = 3). n = number of vessels (one per animal).