Heme oxygenase-1 expression in rats with acute lung rejection and implication

This study investigated the expression of hemeoxygenase-1 (HO-1) in rats with acute lung rejection and its implication.A valid rat orthotopic left lung transplantation model (SD rat→Wistar rat) was established by using an improved three-cuff anastomosis technique.The rats were divided into control group,CoPP (HO-1 inducer)-treated group and ZnPP (HO-1 inhibi-tor)-treated group.The severity of acute rejection was graded on the basis of the morphologic changes of the lung samples stained with HE.The expression of HO-1 protein in lung tissue was de-tected by using immunohistochemistry and Western blot,and HO-1 mRNA activity was assayed by RT-PCR.The results showed that the expression of HO-1 protein was significantly increased with the acute rejection grading in rats (P<0.01).As compared with control and ZnPP-treated groups,the se-verity of acute rejection was not alleviated and the grade not reduced significantly in CoPP-treated group (P>0.05).It was concluded that HO-1 protein might be involved in the pathological process of post-graft acute rejection.The expression of HO-1 protein was increased gradually with aggravation of acute rejection,and HO-1 protein might be used as an index to monitor acute rejection after lung transplantation.