Detection of micronuclei in peripheral blood of mitomycin C-treated mice using supravital staining with acridine orange.
The induction of micronuclei in peripheral blood from mitomycin C (MMC)-treated mice was examined using a supravital acridine orange staining method. Male ICR mice were intraperitoneally given MMC at a single dose of 0.25, 0.5, 1, or 2 mg/kg. Blood was sampled from the tail 24, 48, 72, and 96 h after treatment, and the frequency of micronucleated reticulocytes (MNRETs) was examined. The induction of MNRETs peaked at 48 h after treatment with MMC; there was a clear, dose-related increase in MNRETs. In a multiple-treatment study, mice were treated with 4 consecutive daily injections of MMC at a dose of 0.13, 0.25, 0.5, or 1 mg/kg. The frequency of MNRETs increased markedly 24 h after the second treatment as compared with the first treatment, and did not change significantly until 24 h after the fourth treatment. The frequency of MNRETs decreased to approximately control values 96 h after the last treatment. In addition, a slight but statistically significant increase in the number of micronucleated normochromatic erythrocytes in peripheral blood was detected by means of Giemsa staining 7 days after the last treatment. These results confirm the usefulness of the supravital acridine orange staining method to evaluate micronucleus induction in mouse peripheral blood.
Hara
M
M
Environmental Health Science Laboratory, Sumitomo Chemical Co., Ltd., Osaka, Japan.
Nakagawa
S
S
Fujioka
E
E
Ayukawa
E
E
Izushi
T
T
D000165:Acridine Orange; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D015162:Micronucleus Tests / Q000379:methods; D016685:Mitomycin / Q000633:toxicity*; D009153:Mutagens / Q000633:toxicity*; D012156:Reticulocytes / Q000187:drug effects*
D009153:Mutagens; D016685:Mitomycin; D000165:Acridine Orange