Abstract:Aim To explore the changes of plasma tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI) activity,collagen degradation and osteopontin gene expression during vascular restenosis development. Methods The activities of tPA and PAI were measured by tPA and PAI kits, Northern blotting was used to detect osteopontin gene expression. Results The activity of tPA increased at 3 d after de-endothelization, and peaked at 7 d , the level of tPA increased from 296.1±120.2 IU/L (control group) to 856.2±195.3 IU/L (7 d). The results of hydroxyproline concentration showed that the collagen degradation increased at 3 d and peaked at 7 d after de-endothelialization, about 1.6 times compared with the control. Osteopontin gene expression was remarkably induced by de-endothelization, the peak expression was at 3 d after operation, and was about 5 times comparing with the control, then osteopontin gene expression decreased and returned to the control level at 14 d after operation. Conclusions Osteopontin, collagen turnover and tPA take part in the process of vascular remodeling during vascular restenosis development.