Avian Pathol: Nuclear abnormalities in erythrocytes of parrots (Aratinga canicularis) related to genotoxic damage.

Nuclear abnormalities in erythrocytes, as micronuclei and nuclear buds (BE), are considered potential biomarkers of genotoxic exposure. We described previously the frequency of spontaneous micronucated erythrocytes (MNE) in the species Aratinga canicularis. Here, we have used this species to evaluate the induction of MNE and BE by mitomycin-C. Animals were given a single intracoelomic injection of 0, 2, 3, or 4 mg/kg mitomycin-C on 2 consecutive days. A drop of blood was obtained after 0, 24, 48, and 72 hours, and stained smears were used to count micronucleated polychromatic erythrocytes (MNPCE) and polychromatic erythrocytes with buds (BPCE) per 1000 polychromatic erythrocytes. The number of MNE and BE in 10 000 total erythrocytes was also counted. MNPCE and BPCE frequencies were elevated at 24, 48, and 72 hours after the administration of the lower dose (P < .03). At a 3 mg/kg dose, the frequency of MNPCE increased at 48 and 72 hours (P < .04) whereas the number of BPCE increased, but not significantly. Administration of 4 mg/kg mitomycin-C increased the number of MNE observed at 72 hours (P < .03), the number of MNPCE at 48 hours (P < .01) and 72 hours (P < .006), the BE frequency at 72 hours (P < .05), and the frequency of BPCE at 48 and 72 hours (P < .001). While mitomycin-C appears to produce a parallel increase in MNPCE and BPCE frequencies, the MNE seemed to be a more sensitive indicator of genotoxicity than the BE. This suggests that evaluating BE and MNE in routine hematologic analysis should be considered to evaluate environmental genotoxic exposure.

2006;35:206-210.