FLOW CYTOMETRIC ANALYSIS OF MICRONUCLEUS INDUCTION IN MOUSE ERYTHROCYTES BY GAMMA-IRRADIATION AT VERY-LOW DOSE-RATES

ZETTERBERG G GRAWE J

G. Zetterberg et J. Grawe, FLOW CYTOMETRIC ANALYSIS OF MICRONUCLEUS INDUCTION IN MOUSE ERYTHROCYTES BY GAMMA-IRRADIATION AT VERY-LOW DOSE-RATES, International journal of radiation biology, 64(5), 1993, pp. 555-564

17

INGLESE

Article

Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology

International journal of radiation biology → ACNP

0955-3002

64

5

1993

555 - 564

ISI

0955-3002(1993)64:5<555:FCAOMI>2.0.ZU;2-X

Male CBA-S mice were subjected to protracted gamma-irradiation. Two gr oups of five animals were each exposed to dose rates of 6 and 30 mGy/d ay for 56 days, respectively, upon which irradiation was terminated an d the groups were followed for an additional 49 days. Frequencies of m icronucleated poly- and normochromatic erythrocytes in peripheral bloo d samples were determined before. (day 0), during (day 14, 28 and 56), and after (day 70 and 105) irradiation using flow cytometry. A second experiment was performed as above, but with exposure limited to 7 day s. Frequencies of micronucleated polychromatic erythrocytes in bone ma rrow and peripheral blood were determined. Significantly elevated freq uencies of micronuclei in peripheral blood polychromatic erythrocytes were found for the 30-mGy/day dose group on day 14, 28 and 56 and for the 6-mGy/day dose group on day 28 and 56. In normochromatic erythrocy tes from peripheral blood significantly elevated frequencies were foun d on all sampling occasions with mouse given 30 mGy/day, while those g iven 6 mGy/day showed significantly elevated frequencies on day 28, 56 and 70. The frequencies of micronucleated polychromatic erythrocytes were found to be similar in bone marrow and peripheral blood, while th e frequencies of micronucleated normochromatic erythrocytes were consi stently lower than for micronucleated polychromatic erythrocytes at al l samplings for all groups. On day 28 the frequencies (mean +/- SE) of micronucleated polychromatic erythrocytes in peripheral blood were 0. 0016 +/- 0.0001 for the control group, 0.0019 +/- 0.0001 for the 6-mGy /day group and 0.0028 +/- 0.0003 for the 30-mGy/day group. The results show an elevated induction of micronuclei in erythroblasts at a dose rate of approximately 3 mGy per cell cycle.