OBJECTIVES: Adrenomedullin (ADM) production and secretion have been reported in endothelial cells. The present study was designed to assess whether coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) affect plasma ADM levels. DESIGN AND METHODS: We measured plasma concentrations of ADM using a specific radioimmunoassay method in patients undergoing coronary angiography or PTCA before and after a 5-minute procedure. Patients were divided into three groups; group I: normal coronary angiography group (11 males, 10 females; mean age 55.90 +/- 11.03 yrs), group II: coronary artery disease (CAD), only coronary angiography performed (14 males, 8 females; mean age 60.95 +/- 9.80 yrs), group III: PTCA performed in patients with CAD (35 males, 11 females; mean age 55.89 +/- 10.41 yrs). RESULTS: The plasma ADM levels and left ventricular end diastolic pressures measured before the procedure were similar in the three groups (p > 0.05). Plasma ADM levels were 13.98 +/- 2.26, 15.59 +/- 6.70, 17.15 +/- 8.47 pg/ml respectively. ADM levels measured after CA showed no significant difference in group I (13.75 +/- 1.75 pg/ml) or group II (16.50 +/- 7.18 pg/ml) (p > 0.05). A marked elevation was observed in group III with ADM levels of 27.31 +/- 12.27 pg/ml after PTCA (p < 0.01). The ADM levels observed in group III after PTCA were significantly higher than those of group I and group II after coronary angiography (p < 0.001). CONCLUSION: The results of our study show an increase of ADM after PTCA but not after coronary angiography in patients with or without CAD. We think that the increase of ADM levels may be due to cardiac secretion from endothelial and smooth muscle cells following balloon injury.