Sega G A, Generoso E E, Brimer P A
Biology Division, Oak Ridge National Laboratory, Tennessee 37831-8077.
Environ Mol Mutagen. 1990;16(3):137-42. doi: 10.1002/em.2850160302.
A study of meiotic and postmeiotic germ-cell-stage sensitivity of male mice to induction of unscheduled DNA synthesis (UDS) by acrylamide showed that DNA repair could be detected in early spermatocytes (after the last scheduled DNA synthesis) through about mid-spermatid stages. No DNA repair could be detected in later stages. The maximum UDS response was observed 6 hr after i.p. exposure and was about 5 times greater than the response measured immediately after treatment. This is the longest delay between chemical treatment and maximum UDS response yet observed in mouse germ cells. There was a linear relationship between the UDS response and acrylamide exposure from 7.8 to 125 mg/kg. By using 14C-labeled acrylamide it was determined that the temporal pattern of adduct formation in testes DNA paralleled that of the UDS response, with maximum binding occurring 4 to 6 hr after exposure. In contrast, the temporal pattern of adduct formation in liver DNA showed maximum binding within 1 to 2 hr after exposure and was an order of magnitude greater than that found for the testis DNA.
一项关于雄性小鼠减数分裂期及减数分裂后生殖细胞阶段对丙烯酰胺诱导的程序外DNA合成（UDS）敏感性的研究表明，在早期精母细胞（最后一次预定DNA合成之后）直至大约精子细胞中期阶段均可检测到DNA修复。在后期阶段未检测到DNA修复。腹腔注射暴露6小时后观察到最大UDS反应，该反应比处理后立即测量的反应大约大5倍。这是在小鼠生殖细胞中观察到的化学处理与最大UDS反应之间最长的延迟。UDS反应与7.8至125mg/kg的丙烯酰胺暴露之间存在线性关系。通过使用14C标记的丙烯酰胺确定，睾丸DNA中加合物形成的时间模式与UDS反应的时间模式平行，暴露后4至6小时出现最大结合。相比之下，肝脏DNA中加合物形成的时间模式在暴露后1至2小时内出现最大结合，且比睾丸DNA中的加合物形成数量级更大。
