Adhesion of activated leukocytes to the endothelium as a result of myocardial ischemia/reperfusion has been shown to be involved in the development of tissue injury. Leukocyte adhesion to the endothelium occurs via adhesion molecules expressed on the surface of both cell types. Upon cell activation these proteins may be released into the circulation and measured in a soluble form.
To verify whether the dipyridamole stress test, performed in patients with ischemic heart disease (IHD) and in patients with syndrome X, modifies plasma levels of the soluble adhesion molecules vascular cell adhesion molecule-1 (VCAM-1), intracellular adhesion molecule-1 (ICAM-1), E-selectin and L-selectin.
Plasma levels of the soluble endothelial adhesion molecules ICAM-1, VCAM-1 and E-selectin, as well as of the soluble leukocyte adhesion molecule L-selectin, were measured in venous blood samples taken before and 7 min after administration of dipyridamole in patients with IHD, patients with syndrome X and healthy individuals. Myocardial perfusion was evaluated using single photon emission tomography. The plasma levels of soluble VCAM-1, ICAM-1, E-selectin and L-selectin were all measured using enzyme-linked immunosorbent assays.
After infusion of dipyridamole, plasma levels of ICAM-1 increased significantly in patients with IHD, whereas they remained unchanged in patients with syndrome X and in the control group. In patients with IHD, the initial plasma levels of VCAM-1, E-selectin and L-selectin, before administration of dipyridamole, were higher than those observed in patients with syndrome X and than those in the control group. Plasma levels of soluble VCAM-1, E-selectin and L-selectin decreased significantly in patients with IHD following the dipyridamole stress test, whereas they remained unchanged in patients with syndrome X, and in the control group.
In patients with IHD, administration of dipyridamole induces myocardial ischemia resulting in modification of plasma levels of the soluble adhesion molecules.