OBJECTIVETo observe the effects of interleukin-8 monoclonal antibody on smooth muscle cell proliferation and balloon inflation-induced abdominal aorta stenosis in rabbits.

METHODSThirty-six New Zealand white rabbits were randomly assigned to balloon inflation group (group A, n = 12), interleukin-8 monoclonal antibody pre-treated rabbits (2 mg/kg for 3 days before balloon inflation, group B, n = 12) and sham-operated control group (group C, n = 12). Peripheral blood was collected before experiment and at 4 h, 1, 3, 7, 14, and 28 days post balloon inflation or sham operation and the levels of IL-8 were measured by enzyme linked immunosorbent assay (ELISA). The ratio of positive and negative masculine cells in the high power microscopic field was determined in proliferating cell nuclear antigen (PCNA) stained slide. Histopathologic examination was performed in abdominal aorta and luminal area, intima and tunica media area were measured.

RESULTSPlasma interleukin-8 began to rise at 4 h and peaked at 1 day and remained increased up to 28 days after balloon inflation in rabbits of group A, plasma interleukin-8 level in group A was significantly higher than in group B and C at 4 h and thereafter post operation. The ratio of positive and negative masculine cells was significantly increased in group A compared to group C and was significantly lower in group B than in group A. Abdominal aorta stenosis, luminal area, intima and tunica media area were significantly reduced in group B than in group A. Correlation analysis indicated that there were positive relations between plasma IL-8 level and intima thickness, area of intima and tunica media, respectively (r = 0.894, 0.783, 0.801, 0.912, all P < 0.01).

CONCLUSIONSPlasma IL-8 level is increased in this abdominal aorta stenosis model and is positively correlated to the severity of abdominal aorta stenosis. IL-8 monoclonal antibody could significantly reduce abdominal aorta stenosis in this abdominal aorta stenosis model.