Adhesion molecules play an important role in the development and course of coronary atherosclerosis. In this study, soluble forms of vascular cell adhesion molecule (VCAM-1) intercellular adhesion molecule-1 (ICAM-1), E-selectin and P-selectin were evaluated in patients with various clinical presentations of coronary atherosclerosis and compared them to those with angiographically documented normal coronary arteries. Venous plasma samples were collected from 43 patients with acute myocardial infarction (AMI), 45 with unstable angina pectoris (UAP), 34 with stable angina pectoris (SAP) and 29 subjects with normal coronary arteries (control). The VCAM-1 level was significantly higher in patients with AMI (mean +/- SEM; 799.8 +/- 26.3 ng/ml) than those with UAP (644.2 +/- 26.7 ng/ml) and SAP (526 +/- 32.5 ng/ml) and controls (270 +/- 26.8 ng/ml). In patients with UAP, VCAM-1 was found to be significantly elevated as compared to the SAP group and controls. VCAM-1 level was also higher in SAP group than the controls. Serum levels ICAM-1 were similar among patients with AMI (424.1 +/- 15.2 ng/ml), UAP (403 +/- 12.3 ng/ml) and SAP (381.2 +/- 16.2 ng/ml); however, levels of ICAM-1 was significantly elevated in these groups as compared to the controls (244.3 +/- 11). The mean level of E-selectin was not different in AMI and UAP groups (47.2 +/- 2.2 vs. 42.6 +/- 2.1 ng/ml; respectively). However, it was significantly higher in acute coronary syndrome groups as compared to SAP (33.4 +/- 2.3 ng/ml) and control subjects (30.7 +/- 1.9 ng/ml). Serum levels of E-selectin were similar in SAP group and controls. For P-selectin, no significant difference was observed between AMI and UAP groups (187.5 +/- 7.2 vs. 181.7 +/- 4.7 ng/ml; respectively), however, it was significantly higher in both groups as compared to SAP group (146.1 +/- 7.4 ng/ml) and controls (108 +/- 6.6 ng/ml). Serum level of P-selectin was significantly higher in patients with SAP than the control group. In conclusion, determination of serum VCAM-1, E-selectin and P-selectin levels seems more useful for detecting coronary plaque destabilization.