Influence of 50-Hz Sinusoidal Electromagnetic Field on Hepatic and Pulmonary Phase I and II Drug-Metabolizing Enzymes in Mice

Abstract

The regulatory effect of 50-Hz electromagnetic field exposure was studied on the phase I (activation) and phase II (detoxification) drug-metabolizing enzymes that convert foreign/endogenous chemicals to their active forms and also to forms that could be readily excreted. Mice were exposed to field intensities of 2 and 10 mT, 8 h/day for 8 weeks. Phase I enzymes, cytochrome P-450 and NADPH cytochrome P-450 reductase, were elevated in the liver, and cytochrome P-450 and aryl hydrocarbon hy-droxylase were increased in the lungs at 2 mT. Exposure to 10 mT had little overall effect on phase I enzymes. Phase I1 detoxifying enzymes, mainly glutathione S-transferase, was downregulated at 2 and 10 mT in the liver and lungs; an increase in reduced glutathione levels at 2 mT may play a protective role. Our data suggest that a magnetic field of 2 mT seems to be more potent in the activation of phase I drug-metabolizing enzymes accompanied by increased levels of reduced glutathione, a strong endogenous antioxidant.

Key Words:

• Electromagnetic field
• Drug-metabolizing enzymes
• Xenobiotics
• Cytochrome P-450