Inhibition of Adhesion Molecules Markedly Ameliorates Cytokine-Induced Sustained Myocardial Dysfunction in Dogsin vivo

Adhesion molecules are key molecules for inflammatory cardiovascular diseases and are known to be up-regulated by inflammatory cytokines. However, the role of adhesion molecules in the cytokine-induced myocardial dysfunctionin vivoremains unclear. This role was examined in our novel canine model, in which chronic treatment of the heart with IL-1β-bound microspheres (MS), but not control MS, causes sustained myocardial dysfunctionin vivo. The expression of P-selectin (mRNA and immunoreactivity) was more prominent in the IL-1βgroup than in the control group (treated with control MS alone) after MS injection. The extent of neutrophil infiltration and myocardial myeloperoxidase (MPO) activity were significantly increased in the IL-1βgroup (P<0.01). Pre-treatment with SLeX-OS (a novel oligosaccharide analog of sialyl Lewis^X) or PB1.3 (a monoclonal antibody to P-selectin) prevented the myocardial dysfunction and significantly suppressed the neutrophil infiltration and the increase in myocardial MPO activity induced by IL-1β(P<0.01 each). These results indicate that adhesion molecules play an important role in the pathogenesis of the cytokine-induced sustained myocardial dysfunction in dogsin vivo.