title: Comparison of separated erythrocyte preparations and manual smears of bone marrow in showing micronucleus induction by clastogens and aneuploidogens in mouse.
abstract: The removal of nucleated cells from bone marrow cell suspensions by cellulose column separation and further purification in a Percoll gradient, coupled with slide preparation by a cytocentrifuge, produces uniform preparations of pure well-spread erythrocytes. The use of separated erythrocytes has been a considerable improvement in the in vivo micronucleus (MN) assay, because the optimal cell morphology and the possibility of scoring a high number of polychromatic erythrocytes (PCEs) in a short time are factors contributing to the sensitivity of the assay. As the separation procedure may selectively retain cells containing MN, a study comparing the performance of the erythrocyte fractionation technique and standard manual smear preparation was conducted in male NMRI mice treated with a single injection of two clastogens (cyclophosphamide, 25 or 50 mg/kg, or methylmethane sulfonate, 40 or 80 mg/kg) or two aneuploidogens (colchicine, 0.5 or 1 mg/kg, or vincristine sulfate, 0.05 or 0.1 mg/kg). Both the preparation methods were clearly able to detect the MN-inducing and toxic effects of the treatments. After treatment with cyclophosphamide and methylmethane sulfonate, the frequency of micronucleated PCEs (MNPCEs) was, respectively, 1.6 and 1.8 times higher in the fractionated erythrocytes than in whole bone marrow. Morphological characterization of the MN indicated that this phenomenon was due to improved identification of small micronuclei in the flat cytospun cells of the fractionated erythrocyte preparations. On the other hand, the purified erythrocyte slides contained only about half the number of MNPCEs observed in standard smears, in samples collected from mice treated with colchicine.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000782:Aneuploidy; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002469:Cell Separation / Q000379:methods; D003078:Colchicine / Q000633:toxicity*; D003520:Cyclophosphamide / Q000633:toxicity*; D004912:Erythrocytes / Q000166:cytology* / Q000187:drug effects; D008297:Male; D008741:Methyl Methanesulfonate / Q000633:toxicity*; D051379:Mice; D008815:Mice, Inbred Strains; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D012680:Sensitivity and Specificity; D014750:Vincristine / Q000633:toxicity*
chemical_list: D009153:Mutagens; D014750:Vincristine; D003520:Cyclophosphamide; D008741:Methyl Methanesulfonate; D003078:Colchicine