Apoptosis in the process of limb allograft in rats / 中国组织工程研究

ABSTRACT

BACKGROUND: Limb allograft is a sort of composite tissues allotrans plantation(CTA), some researches showed that the apoptosis of target cell is one of the main mechanism of the dysfunction of allograft.OBJECTIVE: To investigate the characteristic of cell apoptosis in acute rejection of limb allograft in rats based on limb allograft model.DESIGN: A randomized controlled trial using the experimental animals as the objects.SETTING: Experimental animal center Laboratory of a hospital of a medical university MATERIALS The experiment was done in the Experimental Animal Central Laboratory of the First Affiliated Hospital of Harbin Medical University from November 2003 to May 2004. Totally 56 healthy and male SD rats and 28 Wister rats were involved with body mass of 200 to 250 g. The rats were provided by the Experimental Animal Center of the First Affiliated Hospital of Harbin Medical University. They were randomly divided into two groupstransplantation group with 28 Wistar rats and 28 SD rats and control group with 28 SD rats.INTERVENTIONS: The transplantation group of SD rats underwent limb allotransplantation from allogenetic Wistar. The control group of SD rats underwent limb replantation. The expression of acute rejected in limb allografts was observed. The limb grafts were harvested atday 1, 3, 5 or 7 after transplantation. Histopathological rejection grade of each tissue rejection was performed with hematoxylin-eosin staining. Apoptotic cells were detected by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling) and apoptotic index(AI) was calculated.MAIN OUTCOME MEASURES: Primary results: ① istopathological grade of acute rejection in limb allografts ② The relationship between apoptosis and acute rejection in limb allograft in rats; Secondary results:General condition of rats in each group.RESULTS: The limb grafts showed edema and erythema and the skin became red at day(3.43 ±0.79) after transplantation. The average survival time was(7.42 ± 1.72) days. The acute rejection in skin was the strongest. On the day 3, 5 and 7 after operation, the histopathological rejection grades of skins in the transplantation group were(1.14±0.38) ,(2.28 ±0.48) and(2.86 ±0.38) grades respectively. They were significantly different from that of muscle and nerve( P ＜ 0.05 ) . The apoptotic cells in allografts were mainly infiltrating lymphocytes in subcutaneous tissues and then the muscle cells. All was positively correlated with acute rejection grade in limb allograft .CONCLUSION: Apoptosis was involved in acute rejection of limb allograft in rat. The apoptotic index can be used as a quantitative index to estimate the injury of grafts.