To investigate the radiotoxicity to bone marrow in mice after Sr therapy sensitized by nicotinamide and 89 carbogen in mice

the mice were divided into 5 groups: negative control (saline)

positive control (89Sr)

89Sr+nicotinamide

89Sr+Carbogen and 89Sr+nicotinamide+carbogen. 89SrCl was intravenously injected as a bolus containing activities of 7400kBq / 200μL and saline was administrated in equal volume in the negative control group. 1

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15

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60 and 90 days after injection the mice were killed for micronuclei assay in femoral marrow polychromatic erythrocytes (PCE). The average frequency of polychromatic erythrocytes micronuclei (MnPCEs) showed a dual peak. The first maximum MnPCEs frequency occurred between the 2nd and the 4th day

and the second between the 10th and the 14th day. A significant statistic difference on the MnPCEs frequency was found between the negative and the positive control group (P<0.01

F=15.517)

while no difference among 89Sr+N+C

Sr

Sr+N and 89 89 89Sr+C was found (P>0.05). There is also no significant difference on MnPCEs frequency between Chinese Kunming Mice

NIH mice

BALB/c and F1 mice (P>0.05). Although the intervention of radio sensitizer accelerated the occurrence of micronulei in PCE

there was no significant statistical difference between the groups with or without radio-sensitizer. The administration of radio-sensitizer did not aggravate the toxicity on marrow.