新生动物同种主动脉带瓣管道移植物α-actin和PCNA的免疫组织化学研究

Immunohistochemistry study about expression of α-actin and PCNA on implanted valved aortic homograft conduit of neonate rabbit

目的 应用免疫组织化学方法观察新生动物的同种主动脉带瓣管道 (VAHC)移植后平滑肌肌动蛋白 (α- actin)和增殖细胞核抗原 (PCNA)表达的变化 .方法 体质量 15 0～2 0 0 g的新西兰兔 2 4只作为 VAHC的供体 ,0 .9～ 1.2及2 .1～ 2 .9kg的幼兔和成年兔各 12只为受体 .建立新生兔的VAHC移植模型 ,术后 1和 6 mo分别取材作组织学检查和免疫组织化学染色 ,观察 VAHC的组织结构、α- actin及 PCNA阳性表达情况并作计算机图像分析 .结果 组织学检查显示VAHC血管壁三层结构存在 ,内膜及中层均增厚 ,管壁有少量单核细胞及淋巴细胞浸润 ,植入成年兔体内 6 mo的变化最为明显 .免疫组化染色 α- actin在各组 VAHC血管壁中层均呈阳性表达 .与对照组相比 , ～ 组血管壁中层 SMC, , 组内膜及瓣膜内皮细胞 (EC) PCNA阳性指数明显增高 (P<0 .0 5 ) , 组尤为显著 (P<0 .0 1) .图像分析结果表明 , , 组 α- actin的灰度值明显低于对照组 (P<0 .0 5 ) , ～ 组血管壁及瓣膜 PCNA阳性细胞的灰度值低于对照组 (P <0 .0 5 ) .结论 新生兔 VAHC植入幼兔及成年兔体内后的变化呈较明显的慢性排异反应征象 .

AIM Changes of alpha smooth muscle actin (α actin) and proliferating cell nuclear antigen (PCNA) were investigated in the implanted valved aortic homograft conduit (VAHC) of neonate rabbit in heterotopic model using immunohistochemistry method. METHODS Neonatal New Zealand rabbits (weight: 150~200 g, n=24) were used as donors of the VAHCs, young (0.9~1.2 kg, n=12) and adult rabbits (2.1~2.9 kg, n=12) as recipients. The specimens were studied under microscopy and their positive expression of α actin and PCNA by the technique of immunohistochemistry 1 month and 6 months after the implantation. RESULTS Light microscopic examination of the explanted VAHCs revealed intimal and media proliferation, cellular infiltration and valvular thickening. The most obvious changes were found in the adult recipients 6 months after the implantation. A positive expression of α actin was observed in the media of the vessel walls of VAHCs. Indices of PCNA of the media SMC in group Ⅰ to Ⅲ, intima and valve EC in groupⅠ and Ⅲ were higher vs control group (P<0.05), which in group Ⅳ were much higher s control (P<0.01). The imaging analysis indicated that grey level values of α actin in group Ⅱ and Ⅳ, PCNA positive cells of the walls and cusps in group Ⅱ to Ⅳ was lower vs control (P<0.05). CONCLUSION The implanted VAHCs of neonate rabbits manifest obvious chonic immunological rejection. The results indicate that donor-recipient histocompatibility and immunosuppression treatment may have marked therapeutic effects at the time of the small VAHC implantation.