Effects of electromagnetic fields and gender on neurotransmitters and amino acids in rats

Epidemiological studies have linked electromagnetic field (EMF) exposure to certain forms of cancer, however only limited laboratory evidence supports a connection between EMF and biological effects. In the present study we exposed male and female rats to low level, 1000 milli-Gauss (mGs), direct current EMF generated with Helmholtz coils for 1 mo or 4 mo. The effects of these EMF exposures on regional brain neurotransmitter metabolism and circulating amino acid concentrations were determined. After 1 mo of EMF exposure the concentration of serotonin was elevated in the hypothalamus of male rats. Levels of the dopamine metabolite, 3-methoxytyramine, were increased in the corpus striatum of male and female rats that were exposed to EMF for 1 mo. Hypothalamic concentration of norepinephrine was elevated in both groups of male rats, as compared to respective female groups, but was not affected by EMF. Similarly, levels of tyrosine were increased in hypothalamus, corpus striatum and nucleus accumbens of male rats, but were not affected by EMF exposure. Following 4 mo of EMF exposure, no significant effect of EMF was observed. Significant sex differences in plasma amino acid concentrations were observed in both studies, with female rats exhibiting decreases in a majority of the amino acids measured. These results are suggestive that short-term exposure may cause small alterations in neurotransmitter metabolism and in circulating amino acids, which dissipate when exposure duration is increased.