Magnetic resonance imaging (MRI) effects on rat pineal neuroendocrine function.

This study investigated the effects of MRI on receptor-mediated activation of pineal gland indole biosynthesis. Exposure of rats to MRI reduced the effects of isoproterenol on pineal serotonin and N-acetylserotonin levels suggesting that strong magnetic fields and/or radio-frequency pulsing used in MRI inhibited beta-adrenergic activation of the gland. There was no effect of MRI on saline controls.