Krishna G, Hayashi M
Department of Worldwide Preclinical Safety, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, 2800 Plymouth Road, Ann Arbor, MI 48105, USA.
Mutat Res. 2000 Nov 20;455(1-2):155-66. doi: 10.1016/s0027-5107(00)00117-2.
In vivo rodent micronucleus assay has been widely used to detect genotoxicity. Evaluation of micronucleus induction is the primary in vivo test in a battery of genotoxicity tests and is recommended by the regulatory agencies around the globe to be conducted as part of product safety assessment. The assay, when performed appropriately, detects both clastogenicity and aneugenicity. Methods for performing micronucleus evaluation have evolved since its initial description in the 1970s. In recent years, the focus has been directed toward improving micronucleus detection with high efficiency by proposing data-based recommendations to the standard initial protocol design. Such improvements include, e.g., the use of appropriate harvest time(s), inclusion of one or both sexes, number of doses tested, limit dose, integrating micronucleus assessment into the routine toxicology studies, use of fluorescent staining, automation of micronucleus detection and assessment of micronuclei in multiple tissues. This protocol paper describes: the mechanism of micronucleus formation, a generalized protocol for manual detection, enumeration of micronuclei, and data interpretation in light of published information thus far, on the regulatory aspects of this assay. Certain recent protocol issues that are practical in nature are equally valid in relation to standard manual method and provide robust database, which are also included for consideration. It is expected that such improvements of the protocol will continue to drive the utility of this assay in the product safety assessment.
体内啮齿动物微核试验已被广泛用于检测遗传毒性。微核诱导评估是一系列遗传毒性试验中的主要体内试验，全球监管机构建议将其作为产品安全评估的一部分进行。该试验在适当进行时，可检测染色体断裂剂和非整倍体诱导剂。自20世纪70年代首次描述以来，进行微核评估的方法不断发展。近年来，重点一直是通过对标准初始方案设计提出基于数据的建议来提高微核检测的效率。这些改进包括，例如，使用适当的收获时间、纳入一种或两种性别、测试剂量的数量、极限剂量、将微核评估纳入常规毒理学研究、使用荧光染色、微核检测自动化以及在多个组织中评估微核。本方案文件描述了：微核形成的机制、手动检测的一般方案、微核计数以及根据迄今为止已发表的关于该试验监管方面的信息进行数据解释。某些近期具有实际性质的方案问题对于标准手动方法同样有效，并提供了强大的数据库，也将其纳入供考虑。预计该方案的此类改进将继续推动该试验在产品安全评估中的应用。
