Are Oxygen and Related Compounds the Mechanisms Underlying Acupoint Function? A Review of Acupoint Oxygen Specificity Studies.

Oxygen specificity of acupoints has been studied for nearly 30 years. Studies have considered oxygen partial pressure, nitric oxide, carbon dioxide, and other factors. The results of the experiments have shown that the content of oxygen and oxygen-related compounds is statistically significantly different between acupoint and non-acupoint tissues. Despite certain differences in the methods and results across studies, including some contradictory experimental data, most reports agree that metabolic activity, utilization of oxygen, and activity of oxygen-related compounds were higher in acupoint tissues than in non-acupoint tissues. The characteristics of an acupoint may be based on the anatomical structure of the surrounding tissue. Modern sensor needle technology has been widely applied in the study of acupoint oxygen specificity, providing scientific and objective evidence. However, the study of acupoint oxygen specificity has not been without controversy. In order to give practical significance to this research, study design, repeatability of experimental conditions, and homogeneity of subjects should be considered more precisely. Also, more attention should be paid to clinical relevance, i.e., by inclusion of clinical cases and observation of the de-qi effect and clinical responses in the future.