[Monoamine oxidase (MAO) activity in the liver and brain of guinea pigs exposed to an electric field of industrial frequency].

The activity of MAO has been determined in the brain and liver of 36 male guinea-pigs. The animals have been exposed to electric fields of 50 Hz and 100 kV/m frequency. The guinea-pigs have been divided into the following groups (12 animals each): group I--every day 4 hrs' exposure to electric fields (total dose--100 hours), group II--4 hrs' exposure every other day (total dose--100 hours), group III--4 hrs' exposure every third day (total dose--100 hours). The control group consisted of 8 animals. Enzymatic determinations of MAO have been performed by McEven and Cohen's technique, using benzylamine as substrate. A statistically significant increase of MAO activity in brain homogenates of group I and slow decrease in groups II and III, to the control value, has been shown. No changes of the test enzyme have been found in the liver tissue.