Abstract: Objective: To investigate the expression of the vascular cell adhesion molecule-1(VCAM-1) in allograft chronic rejection(CR) after heart transplantation in rats. Methods: The recipient was pretreated with inoculation of donor splenocytes (SPC) followed by cyclophosphamide (CP). Heterotopic cervical heart transplantation was performed. The cardiac allografts were harvested at different stages after heart transplantation. The immunohistochemical method was used to detect the expression of VCAM-1 in the allografts. Results: Preconditioned with SPC followed by CP, the cardiac allografts was prolonged in their survival. Both faint VCAM-1 expression and less lymphocyte infiltration were observed in the SPC and CP - pretreated group. Controversially, the proteins of VCAM-1 were expressed at a high level and significant lymphocyte infiltration was seen in both the nontreated group and the Cyclosporin A (CsA) -treated group. There was no significant difference in the expression of VCAM-1 between the non-treated group and the CsA -treated group（P＞0.05）. Conclusion: The expression level of VCAM-1 is associated with the occurrence and the development of rejection and has positive correlation with the severity of graft rejection. The function of allografts may be predicted and it provides evidence for early diagnosis and prevention of CR by detecting VCAM-1.

Key words: Heart transplantation, Vascular cell adhesion molecule-1, Rejection, Rats