Eight hours of nocturnal 915 MHz radiofrequency identification (RFID) exposure reduces urinary levels of melatonin and its metabolite via pineal arylalkylamine N-acetyltransferase activity in male rats.
Int J Radiat Biol. 2015 Jul 20:1-40. Epub 2015 Jul 20. PMID: 26189731
Hye Sun Kim
PURPOSE: We investigated the effects of whole-body exposure to the 915 MHz radiofrequency identification (RFID) on melatonin biosynthesis and the activity of rat pineal arylalkylamine N-acetyltransferase (AANAT).
MATERIALS AND METHODS: Rats were exposed to RFID (whole-body specific absorption rate, 4 W/kg) for 8 h/day, 5 days/week, for 2 weeks during the nighttime. Total volume of urine excreted during a 24-hour period was collected after RFID exposure. Urinary melatonin and 6-hydroxymelatonin sulfate (6-OHMS) was measured by gas chromatography-mass spectrometry (GC-MS) and enzyme-linked immunosorbent assay (ELISA), respectively. AANAT enzyme activity was measured using liquid biphasic diffusion assay. Protein levels and mRNA expression of AANAT was measured by Western blot and reverse transcription polymerase chain reaction (RT-PCR) analysis, respectively.
RESULTS: Eight hours of nocturnal RFID exposure caused a significant reduction in both urinary melatonin (P = 0.003) and 6-OHMS (P = 0.026). Activity, protein levels, and mRNA expression of AANAT were suppressed by exposure to RFID (P<0.05).
CONCLUSIONS: Our results suggest that nocturnal RFID exposure can cause reductions in the levels of both urinary melatonin and 6-OHMS, possibly due to decreased melatonin biosynthesis via suppression of Aanat gene transcription in the rat pineal gland.