title: Local changes in microcirculation and the analgesic effects of acupuncture: a laser Doppler perfusion imaging study.
abstract: OBJECTIVE
  Although the local response induced by acupuncture manipulation has been considered to be among the important factors that induce the effects of acupuncture, this connection has not yet been properly studied with standardized tools. The aims of this study are to examine the local changes in microcirculation that occur at different manipulation intensities and explore any associations of these changes with the analgesic effects of acupuncture.
  
  
  METHODS
  Twelve healthy volunteers received three acupuncture interventions (insertion only, a single manipulation, and repeated manipulations) at the right LI4 (Hegu or Hapgok) in random order.
  
  
  METHODS
  Skin blood perfusion was measured in a 100-mm(2) area ellipse centered on LI4 by using laser Doppler perfusion imaging (LDPI) before, during, and after acupuncture stimulation. Pressure pain thresholds (PPTs) were measured at ipsilateral areas, including acupoints ST25 (abdomen), LI5 (hand), LI10 (arm), and SP9 (leg).
  
  
  RESULTS
  Repeated acupuncture manipulations enhanced microcirculatory perfusion compared with the insertion-only (p<0.01) and the single-manipulation (p<0.05) conditions. The repeated acupuncture manipulations significantly decreased the pressure pain at ST25 compared with the other groups (each p<0.05). Of note, Spearman correlation analysis revealed significant correlation between changes of local perfusion and PPTs (r=0.393; p=0.018).
  
  
  CONCLUSIONS
  These results suggested that repeated manipulation induced higher local microcirculatory changes that were correlated with the analgesic effects at the relevant sites. The findings suggest that a proper dose of acupuncture stimulation might be essential to elicit the acupuncture effects.
authors.affiliation: 1 Studies of Translational Acupuncture Research, Acupuncture and Meridian Science Research Center, Kyung Hee University , Seoul, Republic of Korea.
authors.forename: Seorim
authors.initials: S
authors.lastname: Min
authors.forename: Hyangsook
authors.initials: H
authors.lastname: Lee
authors.forename: Song-Yi
authors.initials: SY
authors.lastname: Kim
authors.forename: Ji-Yeun
authors.initials: JY
authors.lastname: Park
authors.forename: Younbyoung
authors.initials: Y
authors.lastname: Chae
authors.forename: Hyejung
authors.initials: H
authors.lastname: Lee
authors.forename: Hi-Joon
authors.initials: HJ
authors.lastname: Park
mesh_terms: D015670:Acupuncture Therapy; D000328:Adult; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D017288:Pain Threshold / Q000502:physiology*; D056910:Republic of Korea; D012867:Skin / Q000098:blood supply*; D055815:Young Adult