ID Number		495
Study Type		In Vivo
Model		1.3 GHz (CW, PW) exposure to rats and analysis of blood brain barrier permeability
Details		Wistar rats were exposed to 1.3 GHz (CW & PW) for 20 minutes in the far field in an anechoic chamber at an average power density of 3 mW/cm2. Analysis of brains either immediately or 4 hours after exposure showed an increase in uptake of radio-labeled D-mannitol and inulin, but not dextran (larger MW). The effect seemed to be dependent on peak power and not pulse width. In another study, Sprague Dawley rats were exposed to 2.8 GHz (CW & PW-500 pulses/sec, and a pulse width of 2 usec) for up to 60 minutes at a power densities of 15 mW/cm2. Exposure resulted in an increase in cerebral blood flow in the temporal cortex, visual, auditory, and sensimotor areas of the brain. In a follow up study, however, using 2.8 GHz (PW-500 pulses/sec; 2 usec pulsed wave) exposure for 30 minutes at up to 40 mW/cms, no microwave effects were observed on leakage of 14C sucrose in rat brains.
Findings		Effects
Status		Completed With Publication
Principal Investigator		US Army, Fort Belvoir, VA, USA
Funding Agency		Navy, USA
Country		UNITED STATES
References		Oscar, KJ et al. Brain Res., (1981) 204:220-225 Oscar, KJ et al. Brain Res., (1977) 126:281-293
Comments		In response to critisizm by Preston (1979), the original observations of Oscar and Hawkins (1977) were later determined by the authors themselves to likely be a result of increased blood flow due to temperature effects and not a direct result of increased BBB permeability (1981, 1982).