Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 3: Violet Laser Stimulation in Anesthetized Rats

The aim of this study was to determine the effect of violet laser stimulation on three acupuncture points in anesthetized rats and to test the hypothesis that violet laser light can modulate neurovegetative parameters like heart rate (HR), heart rate variability (HRV), and mean arterial blood pressure (MAP). Recordings were performed in 10 male anesthetized rats under three conditions in Beijing, and monitored with equipment from Graz, where also data analysis was performed. For stimulation a violet laser (emitted wavelength 405 nm, laser output 1 mW, continuous mode) was used. The electrocardiograms were recorded by an HRV Medilog AR12 system during laser acupuncture stimulation of the head, ear, and body (Baihui, "heart" ear acupoint, Zusanli). HR changed significantly only during (P = 0.013) and after (P = 0.038) stimulation at Baihui. Total HRV and the low frequency/high frequency ratio showed insignificant changes. There was an insignificant decrease in MAP after stimulation of Baihui acupoint. Violet laser stimulation offers a method to induce acute effects in HR and HRV in rats. Although the precise mechanism of this effect remains to be determined, alterations are significant. Violet laser stimulation on the Baihui acupoint could readily be translated to clinical studies.