中文摘要：

目的探讨小鼠主动脉性腺中肾（AGM）区基质细胞氨基肽酶N／CD13（APN／CD13）的表达和放射损伤前后该酶活性的变化及意义。方法采用免疫组织化学染色、RT-PCR检测AGM区基质细胞APN／CD13的表达；^60Coγ射线8．0Gy照射细胞，在不同的时间点用分光光度计检测APN／CD13的酶活性。结果AGM区基质细胞APN／CD13呈强阳性表达；放射损伤后酶活性呈一过性降低，继而升高，4h达高峰，24—48h基本恢复至照射前水平。结论APN／CD13在AGM区基质细胞上呈强阳性表达；在放射损伤后酶活性增高，可能是促进造血功能恢复的一种代偿机制。

英文摘要：

Objective To investigate the expression of APN/CD13 in mice embryo AGM stromal cells and the change of its enzymatic activity before and after irradiation. Methods The expression of APN/CD13 in AGM stromal cells was assayed by RT-PCR and immunohistochemistry. The stromal cells in AGM region were irradiated with 8.0 Gy of ^60Co γ-rays, and APN/CD13 enzymatic activity was measured by spectrophotometer at different time points. Results The APN/CD13 expression level was enhanced significantly in AGM stromal cells. The enzymatic activity of APN/CD13 decreased temporally post-irradiation injury, then increased to the highest level 4 hours post-irradiation, and it returned to the level of before irradiation 24 to 48 hours postirradiation. Conclusions The expression of APN/CD13 was remarkable in AGM stromal cells. The enzyme activity of APN/CD13 was temporally enhanced after irradiation, which might be one of the compensatory mechanisms to promote the hematopoietic recovery after irradiation.