Effects of Transcutaneous Xenon Light Irradiation around the Stellate Ganglion on Autonomic Functions

Abstract

[Purpose] The purpose of the present study was to investigate the effects of transcutaneous xenon light irradiation around the stellate ganglion on autonomic functions. [Subjects] Thirty healthy volunteers were the subjects. [Methods] The subjects underwent two experimental sessions: 1) 10-minute xenon light irradiation to the bilateral stellate ganglions in a comfortable supine position (Xe-LISG); and 2) 10-minute rest in the same position as Xe-LISG (control). The low frequency (0.04-0.15 Hz) power (LF) and ratio of LF to the high frequency (0.15-0.40 Hz) power (LF/HF) obtained from power spectral analysis of R-R intervals and skin temperatures of the upper and lower extremities (UE and LE) were examined. [Results] Although no significant changes of HF and LF/HF were observed before and after the control, HF after Xe-LISG was significantly increased compared with that before Xe-LISG, and LF/HF after Xe-LISG was significantly decreased compared with that before Xe-LISG. Additionally, although the UE skin temperature during Xe-LISG tended to be higher than that during the control, the LE skin temperature during Xe-LISG tended to be lower than that during the control. [Conclusion] These results suggest that Xe-LISG inhibits sympathetic activity and induces not only an increase in the UE skin blood flow, but also a decrease in the LE skin blood flow.