Increased body weight in C57BL/6 female mice after exposure to ionizing radiation or 60Hz magnetic fields.
OBJECTIVE
The purpose of this investigation was to determine whether early treatment with ionizing radiation and/or chronic magnetic field (MF) exposure affected body weight in female mice.


METHODS
Weanling C57BL/6 female mice were irradiated with four equal weekly cobalt-60 exposures (total cumulative doses: 3.0, 4.0, 5.1Gy) and/or received chronic lifetime exposure to 1.4 mT 60 Hz circularly polarized MF or ambient MF. The body weights of 2280 mice were recorded at 35 age intervals, and analysis of variance was used to compare the mean differences from baseline weights between treatment groups and sham-exposed controls.


RESULTS
A highly statistically significant effect of ionizing radiation on body weight was observed at 28 age intervals (p < or = 0.001), and for MF exposure at 10 age intervals (p < or = 0.001). During the young adult growth phase, mice exposed only to MF exhibited < or =0.5 g greater weight gain relative to sham-exposed controls (p = 0.0001). The effect of ionizing radiation alone was inversely related to dose, with the largest weight increases observed in all of the irradiated groups after 9-12 months (p = 0.0001).


CONCLUSIONS
Treatment with split-dose ionizing radiation at an early age and chronic exposure to a residential power frequency MF were found to produce small but significant increases in body weight.
Babbitt
J T
JT
Department of Medicine, University of California, Los Angeles, 90095, USA. jbabbitt@ucla.edu
Kharazi
A I
AI
Taylor
J M
JM
Bonds
C B
CB
Zhuang
D
D
Mirell
S G
SG
Frumkin
E
E
Hahn
T J
TJ
D000818:Animals; D001835:Body Weight / Q000502:physiology / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006133:Growth Substances / Q000502:physiology; D016023:Integrins / Q000502:physiology; D008280:Magnetics / Q000009:adverse effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D013997:Time Factors
D006133:Growth Substances; D016023:Integrins; D020928:Mitogen-Activated Protein Kinases