三—（2—甲基—1—氮丙啶）膦化氧在不同组织中诱导的程序外DNA合成

用小组织块高压氧下^H-TdR体外掺入的放射自显影法，对三－（2－甲基－1－氮丙啶）磷化氧（MAPO）在LACA小鼠几种器官组织中诱导的程序外DNA合成（UDS）进行检测。MAPO于体外直接与组织作用及皮下注射后都能诱导肾小管、肾小球、肺泡和支气管上皮的UDS。两种试验中标记细胞百分数及平均银粒数与MAPO浓度及剂量均有量效关系。大剂量体内给药时前胃上皮等组织亦出现UDS，但对肝细胞没有作用。此毕MAPO有基因毒性。

UNSCHEDULED DNA SYNTHESIS INDUCED BY TRIS(2-METHYL-1-AZIRIDINYL)PHOSPHINE OXIDE IN DIFFERENT TISSUES

Unscheduled DNA synthesis (UDS) induced by tris (2-methyl-l-aziridinyl) phosphine oxide (MAPO) was detected autoradiographically in several organs and tissues of LACA mice by using an in vitro method with incorporation of tritiated thymidine into small slices of tissue under 3 atmospheres of oxygen.The results indicated that MAPO can induce UDS in renal tubules,renal corpuscles,pulmonary alveoli and bronchial epithelium in vitro and a more obvious UDS in these tissues was induced after subcutaneous injection.The percentage and the number of net grain per nucleus in labelled cells correlated with the concentration and dosage of MAPO.It also induced UDS in proventriculus epithelium and other tissues in high doses in vivo but no UDS in hepatocytes was induced both in vitro and in vivo. These results show that MAPO is a genotoxic agent.