ABSTRACT
Groups of female BALB/C mice were irradiated with 425-MHz radio frequency (RF) radiation either continuous wave (CW) or pulse modulated (PM, 1-ms pulse width, 250 pulses/s). Mice were irradiated in a rectangular strip-transmission line at average forward powers of 78, 17.7, or 5 W for CW and 17.7, 5, or 1.25 W for PM. The mean specific absorption rate, as measured using twin-well calorimetry was 7.7 W/kg for a forward power of 70 W. No differences in the mitogen-stimulated response of lymphocytes or in the primary antibody response to sheep erythrocytes or polyvinylpyrrolidone were observed between irradiated and sham-irradiated mice, nor between mice exposed to either CW or PM 425-MHz RF radiation.
Subject(s)
Antibody Formation/radiation effects , Lymphocyte Activation/radiation effects , Radio Waves , Animals , Female , Mice , Mice, Inbred BALB CSubject(s)
Body Temperature/drug effects , Microwaves , Serotonin/pharmacology , Animals , Body Temperature/radiation effects , Female , Male , Mice , Mice, Inbred BALB C , Mice, Inbred CBA , Time FactorsABSTRACT
Male CBA/J mice were exposed under far-field conditions in a temperature and humidity controlled environment to 2450-MHz (CW) microwaves. Mice were exposed once for 30 minutes at a power density of 15, 20, 30, or 40 mW/cm2. The whole-body-averaged dose rate was approximately 0.7 mW/g per mW/cm2. Six days after irradiation, the percentage of complement-receptor-positive (CR+) spleen cells was determined. No difference was observed in the percentage of CR+ spleen cells of young adult (10-12-week-old) mice exposed at any of the power densities as compared with sham-irradiated controls. However, a significant (P less than .05) increase was observed in the percentage of CR+ cells from 16-week old mice exposed at 40 mW/cm2. This increase in CR+ cells was accompanied by a significant (P less than .05) decrease in the number of nucleated cells in the spleens of these mice. This change in CR+ and nucleated spleen cells was not consistently produced. The available data indicate that the age and strain of the mouse, the microwave exposure characteristics, and the environmental conditions may all be sources of variation that affect the CR+ end point.
Subject(s)
Microwaves , Receptors, Complement/radiation effects , Spleen/radiation effects , Animals , Male , Mice , Mice, Inbred CBA/immunologyABSTRACT
The parenteral administration of bacterial endotoxin to rats causes a hypothermia that is maximal after approximately 90 minutes. When endotoxin-injected rats were held in a controlled environment at 22 degree C and 50% relative humidity and exposed for 90 minutes to microwaves (2450 MHz, CW) at 1 mW/cm2, significant increases were observed in body temperature compared with endotoxin-treated, sham-irradiated rats. The magnitude of the response was related to power density (10 mW/cm2 greater than 5 mW/cm2 greater than 1 mW/cm2). Saline-injected rats exposed for 90 minutes at 5 mW/cm2 (specific absorption rate approximately 1.0 mW/g) showed no significant increase in body temperature compared with saline-injected, sham-irradiated rats. The hypothermia induced by endotoxin in rats was also found to be affected by ambient temperature alone. Increases in ambient temperature above 22 degree C in the absence of microwaves caused a concomitant increase in body temperature. This study reveals that subtle microwave heating is detectable in endotoxin-treated rats that have impaired thermoregulatory capability. These results indicate that the interpretation of microwave-induced biological effects observed in animals at comparable rates and levels of energy absorption should include a consideration of the thermogenic potential of microwave.