Detection of clastogenic and aneugenic damage in newborn rats

Abstract

The last 25 years have seen an ever-growing use of the erythrocyte micronucleus test for measuring damage to mammalian chromosomes in vivo. In addition, staining micronuclei with antikinetochore antibodies from CREST serum discriminates aneugenic from clastogenic damage. The use of the micronucleus test in rats, however, has been problematic because the spleen of adult rats efficiently removes micronucleated erythrocytes from the blood. In the present study, we have treated 5-day-old rats with either X-rays (a clastogen) or vinblastine (an aneugen) and measured micronuclei in erythrocytes from the blood and liver. Each treatment increased the frequency of micronuclei in both tissues, with the percentages of CREST-staining micronuclei reflecting the mechanism of micronucleus induction by the two agents. The results indicate that performing the micronucleus assay in the liver and peripheral blood of 5-day-old rats may be a useful approach for detecting the in vivo genotoxicity of chemical and physical agents.

Micronucleus test on Triturus carnifex as a tool for environmental biomonitoring

“…In fact, they are in direct contact with the surrounding water, while the germinating cells of the skin are covered by a thin stratum of epidermal cells; nonetheless, differences in cellular turnover, activity, metabolism or DNA repair should not excluded. This work confirms a higher sensitivity of the MN test when applied on younger individuals [National Cancer Institute, ] as observed in mice [Sanderson and Clark, ], rats [Udroiu et al, ], cats [Zúñiga‐González et al, ], pigs [Martinez, ], and humans [Neri et al, ]. We speculate that behind the different MN frequencies observed between adult and larval samples there could be both a difference in tissue‐specific sensitivity and the diverse life habit characterizing the postmetamorph and larval animals, the former being aquatic only during the reproduction period [Vignoli et al, ], whilst the latter being aquatic for the whole life‐stage.…”

Recommended protocols for the liver micronucleus test: Report of the IWGT working group

“…In the JR method, approximately 4-week-old animals have been used, but the use of younger rats (e.g. 5 days old) has also been reported [32]. However, further justification of metabolism equivalency to adult rats may be needed when using much younger rats, and it was agreed that more data were required before the range of animal ages could be recommended.…”

Clastogenicity and aneuploidy in newborn and adult mice exposed to 50 Hz magnetic fields

“…In order to do this, the micronucleus test with CREST staining was performed on erythrocytes from liver (or bone marrow for adults) and peripheral blood. The liver is the main hematopoietic organ from the 11th day of gestation until the first days after birth (Keller et al 1999, Udroiu et al 2006, whereas in adult life this role is played by the bone marrow. While micronucleated erythrocytes from the hemopoietic organ reflect genotoxic damage which occurred in the last 48 h, those from peripheral circulation reflect events that occurred during the last 35 days (Schlegel & MacGregor 1982, Luke et al 1988.…”