Effects of Pulse Microwave Exposure on Mitochondrial Marker Enzyme and Energy Metabolism in Mouse Brain (1)

Chiang H

Paper presented at Erice, Sicily, Italy, November 21-25, 1999

Microwave Lab, Medical college, Zhejiang Univ. Hangzhou, 310006, China

Effects of pulse microwave exposure at various power densities on mitochondrial marker enzyme in mouse brains

Some studies have shown that the pulsed microwave (PW) is more effective in producing nonthermal bioeffects than continuous wave (CW) at the same average power density. In recent years, the bioeffects of ultra-wideband electromagnetic pulses (EMP) have been studied in some countries.

In a previous study of the effect of microwaves on brain ultrastructure, it was concluded that mitochondria are more sensitive to MW than other organelles. We therefore performed quantitative analyses of the mitochondrial marker enzymes succinate dehydrogenase (SDH) and monoamine oxidase (MAO) using histochemical methods.

In the experiment, C57BL mice were used. Four groups were irradiated with PW (carrier frequency 3 GHz, pulse repetition rate 935 and pulse width 1.2 microseconds) at 5, 1, 0.5, or 0.1 mW/cm², respectively. One group was served as control.

The incident power densities were measured with a Narda Model 8623 Isotropic Electromagnetic Radiation Monitor.

The mice were exposed or sham exposed to PW once for 3 hours with their bodies parallel to the E vector. The SAR for the four exposure groups were 5.1, 1.02, 0.51, and 0.1W/kg respectively.

Following irradiation the animals were decapitated. Fresh frozen brain slices were prepared in sagittal section for SDH and MAO, respectively. The enzyme analyses were carried out with an OPTON MPMOTK microspectrophotometer. The mean amount of each enzyme in both the hypothalamus and hippocampus was calculated and compared between the different groups.

The results showed that all irradiated groups except 0.1mW/cm² showed a significant decrease in SDH in both the hypothalamus and hippocampus as compared with the control group.