Pacchierotti F, Tiveron C, D'Archivio M, Bassani B, Cordelli E, Leter G, Spanò M
Section of Human and Environmental Effects, ENEA, CRE Casaccia, Rome, Italy.
Mutat Res. 1994 Sep 1;309(2):273-84. doi: 10.1016/0027-5107(94)90102-3.
Within a project coordinated by the Commission of the European Communities for the detection of germ cell mutagens, the cytogenetic analysis of first-cleavage metaphases was carried out to detect chromosomal damage induced by acrylamide (AA) in meiotic and postmeiotic stages of mouse spermatogenesis. Male mice were intraperitoneally injected with single acute doses of 75 or 125 mg/kg or treated with five daily injections of 50 mg/kg and mated either 7 or 28 days after the end of treatment. Chromosomal aberrations were scored in C-banded metaphases prepared from one-cell zygotes by a mass harvest technique. AA treatment of late spermatids-spermatozoa resulted in significant increases of structural aberrations at all doses tested. The data could be fitted to a curvilinear regression and a doubling dose of 23 mg/kg was calculated. The large majority of observed aberrations were of the chromosome type, including dicentrics, rings and translocations, in agreement with a mechanism of chromosomal damage mediated through the alkylation of DNA-associated protamines. Even though the frequency of aberrations 28 days after treatment was not significantly higher than the control value, the presence of multiple rearrangements in two cells suggested that AA might also have a minor effect on spermatocytes. The results of the cytogenetic analysis of first cleavage metaphases agreed well both qualitatively and quantitatively with the outcome of dominant lethal and heritable translocation assays. AA-induced cytotoxicity was monitored by flow cytometric DNA content analysis of testicular cells. By this method, a dose-dependent depletion of mature spermatids after treatment of spermatogonia and a toxic effect upon primary spermatocytes were detected.
在欧洲共同体委员会协调的一个检测生殖细胞诱变剂的项目中，对第一次卵裂中期进行了细胞遗传学分析，以检测丙烯酰胺（AA）在小鼠精子发生减数分裂和减数分裂后阶段诱导的染色体损伤。雄性小鼠腹腔注射单次急性剂量75或125mg/kg，或每日注射5次，每次50mg/kg，并在治疗结束后7天或28天进行交配。通过大量收获技术，对从单细胞受精卵制备的C带中期染色体进行染色体畸变评分。对晚期精子细胞-精子进行AA处理后，在所有测试剂量下结构畸变均显著增加。数据可拟合为曲线回归，并计算出加倍剂量为23mg/kg。观察到的绝大多数畸变属于染色体类型，包括双着丝粒、环状染色体和易位，这与通过与DNA相关的鱼精蛋白烷基化介导的染色体损伤机制一致。尽管处理后28天的畸变频率并不显著高于对照值，但两个细胞中存在多个重排表明AA可能对精母细胞也有轻微影响。第一次卵裂中期的细胞遗传学分析结果在定性和定量上均与显性致死和可遗传易位试验的结果吻合良好。通过流式细胞术对睾丸细胞的DNA含量进行分析来监测AA诱导的细胞毒性。通过这种方法，检测到精原细胞处理后成熟精子细胞的剂量依赖性减少以及对初级精母细胞的毒性作用。
