Plasma chemotactic activity during dipyridamole induced myocardial ischemia

We have previously reported that transient myocardial ischemia induced during exercise or dipyridamole challenge leads to the release of increased amounts of hydrogen peroxide into circulating blood. It would indicate that the temporary functional changes within myocardial cells may constitute there a sterile inflammatory area. Therefore we decided to evaluate the chemotactic properties of plasma in patients undergoing dipyridamole provocative test, as a sign of released inflammatory mediators. The ischemia occurrence was evaluated with 99mTc-SestaMIBI followed by single photon emission computed tomography (SPECT).

Blood samples were obtained from the peripheral vein of 42 patients (18 men and 24 women, mean age 61 years). Plasma chemotactic activity was determined by the use of the Boyden chamber method: immediately before dipyridamole challenge (time 0), 7, and 30 min after drug infusion. The migration of control polymorphonuclear neutrophils towards evaluated plasma samples was estimated.

Chemotaxis of control PMNs towards plasma isolated from patients without signs of myocardial ischemia 7 min after dipyridamole administration was significantly diminished in comparison with baseline values (p=0.003). Plasma obtained 7 min after dipyridamole infusion from patients manifesting signs of myocardial ischemia by SPECT attracted control PMNs significantly more intensively in comparison to plasma isolated at time 0 (p=0.0005).

The obtained results indicate that transient myocardial ischemia induced by dipyridamole challenge leads to generation of chemotactic factors detectable in peripheral blood plasma.