N-acetyl-cysteine reduces neointimal thickening and procoagulant activity after balloon-induced injury in abdominal aortae of New Zealand white rabbits

Background: Procoagulant activity and oxidative stress generated by balloon injury to normal vessels promote the mi,oration of medial smooth muscle ce lls and their proliferation in the intima. We hypothesised that administeri ng levo N-acetyl-cysteine (NAC) i,v. at the time of injury, and s.c, before and after injury would reduce neointimal formation 4 weeks later and would regulate procoagulant activity in vessels with neointima undergoing balloo ning a second time. Methods and Results: at the time of injury rabbits rece ived: NAG, unfractionated heparin (HEP) or both (NAC + HEP). Neointimal thi ckening at 28 days, calculated as the ratio between the intimal and medial area, was attenuated after NAG, HEP and NAC+HEP by 39%, 30% and 47% respect ively when compared to untreated injured animals (CONTROLS) (p <0.05). At 2 8 days, bound thrombin activity and platelet adhesion Ih after a repeated b alloon injury decreased in animals receiving NAG, HEP and NAC+HEP by 54%, 6 3% and 64% for thrombin activity (p <0.05 vs CONTROLS), and by 56%, 66% and 75% respectively for (111)Indium-platelet deposition (p <0.05 vs CONTROLS) . Conclusions: NAC in-vivo was effective in reducing neointimal thickening and procoagulant response after balloon injury.