evaluation of the effect of gamma ray on erythroid cells in bone marrow oaf Balb/c mice on the base of micronucleous test

In this paper, effect of gamma ray on erythroid cells of bone marrow such as polychlomatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) was assessed after exposure to doses 1, 2, 5, 7. 5,10 Gray. Twenty four hours after exposure, mice were sacrifrced by cervical dislocation and bone marrow of their femurs were extracted. Then, the changes in NCE, PCE and micronucleus cells caused by radiatlon were considered Standard staining and optical microscope have been used to count cells without and with Micronucleus.Result shoed that, relative decreasing of the number of PCE and increasing of the number of micronucleus up to dose of 2 Gray, which showes the cytotoxic and clastogenic effect, respectively. In doses higher than 2 Gray, these changes were not continued, Thus PCE increasing was seen in doses between 5 and 7.5 Gray and its decreasing was seen between 7.5 and 10 Gray. At the same doses, the number of micronucleus was also decreased. Overall, we concluded that Probably defensive mechanisms of Balb/c mice in doses higher than 2 Gray are stimulated Too. Therefore they have more resistance against the destructive gamma ray effects.