Alternate magnetic fields potentiate monoamine oxidase activity in the brain

Catecholamines and serotonin, which act as neurotransmitters and regulate blood circulation, are degraded by monoamine oxidase (MAO) [EC 1.4.3.4.] which exists two iso-enzymes named MAO-A and MAO-B. In this study, the effects of magnetic fields on MAO activity in the rat brain were examined. MAO-A activity was not changed in static magnetic fields (0.1-340 mT) or in 10-500 mT/s of alternate isosceles triangular magnetic fields (AITMF) (50 Hz). MAO-B activity was not changed in static magnetic fields (0.1-340 mT) and in 10, 34, 340, 95, 105, 110, and 340 mT/s of AITMF. However, it was increased to 114% in the 100 mT/s of AITMF. In 100 mT/s, Michaelis constant (K(m)) significantly decreased to 72%, suggesting that the affinity of the substrate to the enzyme also increased. These results indicate that only MAO-B was influenced by AITMF with 'active window' phenomenon, and suggest that AITMF might affect neural activity and hemodynamics by altering MAO-B.