Neutrophil accumulation promotes intimal hyperplasia after photochemically induced arterial injury in mice

The role of leukocytes in the pathogenesis of coronary arterial disease has become a focus for clinical research. The aim of this study was to determine whether neutrophil accumulation would participate in the development of intimal hyperplasia after endothelial injury in mice, and whether d-myo-inositol hexakisphosphate (phytic acid) which inhibits the binding of L- and P-selectin to sialyl Lewis^X could inhibit the development of intimal hyperplasia. Endothelial injury was inflicted in one femoral artery via the photochemical reaction between systemically injected rose bengal and transillumination with green light (wavelength: 540 nm). Scanning electron microscopic observation at 3 days after the injury showed an increase in the number of leukocytes adhering to the injury site. Histological observation at 21 days showed that in the neutropenia group administered anti-neutrophil antibody and in the phytic acid-treated group the progression of intimal hyperplasia was significantly attenuated by comparison with the corresponding control groups. These results suggest that neutrophil accumulation contributes to the initiation and/or development of intimal hyperplasia and L- and/or P-selectin may participate in their mechanisms.