title: A liver micronucleus assay using young rats exposed to diethylnitrosamine: methodological establishment and evaluation.
abstract: We have developed a simple liver micronucleus assay using young rats (up to 4 weeks old) to assess cytogenetic damage of chemicals in liver cells. Diethylnitrosamine (DEN) was used as a model rodent hepatocarcinogen in this study. Compared to the partial hepatectomy method most commonly used for the liver micronucleus assay, the present assay method showed equal or even higher practicability. The young rat liver micronucleus assay was also characterized for rat strain differences, sampling time after treatment, single treatment vs. split treatment, age of animals, administration route, and staining method. Although based on one model chemical, we propose an acceptable protocol for the micronucleus assay using young rat liver as follows: Up to 4-week-old rats should be used; oral or intraperitoneal administration can be used; single or repeated treatment protocols can be applied; sampling time is 3-5 days after the last treatment; hepatocytes are prepared by the collagenase perfusion method; and cells are stained with the AO-DAPI double staining method.
authors.affiliation: Ina Research Inc., Nagano, Japan. h-suzuki@ina-research.co.jp
authors.forename: H
authors.initials: H
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Shirotori
authors.forename: M
authors.initials: M
authors.lastname: Hayashi
mesh_terms: D000165:Acridine Orange; D000284:Administration, Oral; D000367:Age Factors; D000818:Animals; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity*; D002469:Cell Separation / Q000379:methods; D004249:DNA Damage; D004052:Diethylnitrosamine / Q000008:administration & dosage / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005456:Fluorescent Dyes; D006498:Hepatectomy; D022781:Hepatocytes / Q000187:drug effects* / Q000648:ultrastructure; D007211:Indoles; D007274:Injections, Intraperitoneal; D008099:Liver / Q000166:cytology / Q000187:drug effects; D008115:Liver Regeneration; D008297:Male; D015162:Micronucleus Tests / Q000379:methods*; D008938:Mitosis; D051381:Rats; D011916:Rats, Inbred F344; D017207:Rats, Sprague-Dawley
chemical_list: D002273:Carcinogens; D005456:Fluorescent Dyes; D007211:Indoles; D004052:Diethylnitrosamine; C007293:DAPI; D000165:Acridine Orange