title: Variations in energy metabolism along the pericardium meridian and its relationship with visceral function adjustments during electroacupuncture.
abstract: BACKGROUND
  Electroacupuncture (EA) is a traditional Chinese medicine treatment guided by meridian theory. As it gradually gains more worldwide acceptance, a clarification of its mechanisms is extremely urgent. We observed variations in transcutaneous oxygen pressure/carbon dioxide pressure (tcpO2/tcpCO2) and microcirculation blood perfusion units (BPU) along the pericardium meridian, and cardiac function during EA at Neiguan (PC6) to explore variations in energy metabolism and its relationship with visceral function adjustments during EA.
  
  
  METHODS
  Twenty-two healthy volunteers participated in this study. Three channel laser Doppler flowmetry and tcpO2/tcpCO2 detection systems were used to detect tcpO2/tcpCO2 and microcirculation BPU along the pericardium meridian. A hemodynamic monitor was used to detect cardiac function.
  
  
  RESULTS
  In the normal state, the microcirculatory BPU along the pericardium meridian were significantly higher than that of their bilateral corresponding control points (p < 0.05). During EA at PC6, the values of the microcirculatory BPU along the pericardium meridian did not vary, and few increased. In the normal state, the values of tcpO2 along the pericardium meridian were significantly higher than those of their bilateral corresponding control points (p < 0.05). In addition, the values of tcpCO2 along the pericardium meridian were lower than those of their bilateral corresponding control points. In comparison with the normal state, EA could decrease tcpO2 along the meridian significantly (p < 0.05) and increase tcpCO2. During EA at PC6 in healthy volunteers treated by artificial acute mild hypoxia, cardiac output and cardiac index (p < 0.05) decreased and systemic vascular resistance increased significantly (p < 0.05).
  
  
  CONCLUSIONS
  In the normal state, the values of microcirculatory BPU and tcpO2 along the pericardium meridian were both higher than those of their bilateral corresponding control points. Energy metabolism was vigorous along the meridian. During EA, the decrease in oxygen partial pressure along the pericardium meridian might be a result of strengthened energy metabolism of associated tissue and increased oxygen consumption. The variations in energy metabolism along the pericardium meridian during the course of EA had a close relationship with visceral function adjustments.
  
  
  BACKGROUND
  Chinese Clinical Trial Registry ChiCTRTRC13003193.
authors.forename: Shu-Xia
authors.initials: SX
authors.lastname: Zheng
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Pan
authors.affiliation: Fujian Academy of Traditional Chinese Medicine, Class III Laboratory of Acupuncture Physiology, Key Unit of the Propagated Sensation along Meridian of State Administration of Traditional Chinese Medicine, Fuzhou Fujian 350003, China. xujinsenjls@163.com.
authors.forename: Jin-Sen
authors.initials: JS
authors.lastname: Xu
authors.forename: Chun-Ying
authors.initials: CY
authors.lastname: Xiu
authors.forename: Ya-Qin
authors.initials: YQ
authors.lastname: Dong
authors.forename: Xiaoxiang
authors.initials: X
authors.lastname: Zhu
mesh_terms: D015669:Acupuncture Points; D000328:Adult; D000818:Animals; D002245:Carbon Dioxide / Q000378:metabolism; D015671:Electroacupuncture; D004734:Energy Metabolism; D005260:Female; D006321:Heart / Q000502:physiology; D006801:Humans; D008297:Male; D016740:Meridians; D008833:Microcirculation; D010100:Oxygen / Q000378:metabolism; D010496:Pericardium / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen