Metabolomic study of urinary polyamines in rat exposed to 915 MHz radiofrequency identification signal

Metabolomic analysis of urinary polyamines (PAs) from rat exposed to 915 MHz radiofrequency identification (RFID) signal for 8 h/day for 2 weeks was performed by gas chromatography-mass spectrometry as N-ethoxycarbonyl/N-pentafluoropropionyl derivatives. Large alterations in nine PA levels including four aliphatic and five acetylated PAs were monitored in sham-exposed and RFID-exposed groups. Total PA and urinary levels of N ¹-acetylputrescine, N ¹-acetylcadaverine, putrescine, cadaverine, N ¹-acetylspermidine, N ⁸-acetylspermidine, spermidine and spermine were reduced, whereas N ¹-acetylspermine was significantly increased after sham and RFID exposure compared with those before exposure. Their levels were normalized to the corresponding group means before exposure and then plotted into star symbol patterns. N ¹-Acetylspermine after RFID exposure was 54 % higher compared to the level before RFID exposure, while it was elevated by only 17 % in the sham group. The results suggest that 915 MHz RFID exposure may induce metabolic disturbance of PA. It may also elevate spermidine/spermine acetyltransferase (SSAT) activity. Thus, the present metabolic profiling combined with star pattern recognition method might be useful for understanding the complexity of biochemical events after exposure to RFID signal.