Visualization of the Pericardium Meridian with Fluorescent Dyes
Updated: May 11
For over 8000 years, acupuncture and Chinese medicine have been applied to support the healing of diseases and physiologic malfunctions. Chinese acupuncture is based on a system of meridians. Anatomically, acupoints have abundant nerves, muscles, vessels, and tendon but no other visible anatomical structures. Acupuncture meridians traditionally are believed to channels connecting the surface of the body to internal organs.
Evidence-based Complementary and Alternative Medicine recently published a paper showing that researchers have for the first time clearly observed continuous fluorescent lines migrating along with the body's meridian points, work that provides corroboration for the existence of meridians in Chinese medicine. Scientists from the Chinese Academy of Traditional Chinese Medicine and Harvard Medical School were involved in the collaboration.
The team's experiment obtained clear fluorescent dyes images of pericardial meridian over 20cm long in the arm. Dr Tang Qing said this is the first time researchers have used a new tracing method to obtain meridian trajectories in humans since radioisotope tracing was used in the 1980s. This time, the meridian imaging is more stable, and the pathway of multiple points along a meridian is more precise and more reproducible.
Pericardium meridian from The Great Compendium of Acupuncture and Moxibustion
Specifically, Tang Qing said that the team initially used sodium fluorescein, which was then photographed over several hours using laser excitation to capture the fluorescein's migration pathways in the body.
In this study, injection of fluorescein sodium into acupuncture points PC5, PC6, and PC7 was associated with slow diffusion of the dye proximally along a path aligning closely with the pericardium meridian.
The study reinforces the past studies that identified slow-migrating pathways of meridians that travelled at approximately 2.5 cm/min over 11 cm. Direct injections of the dyes into blood vessels led to a much more instantaneous appearance in 10 seconds, while [99mTc] rhenium sulfate—which has a predilection for lymphatics—was detected in axillary lymph nodes after 90 minutes in both acupuncture points and control groups, without a clear pathway.
By comparing ultrasound imaging and infrared imaging, the possibility of the fluorescent line flowing along a blood vessel was ruled out. The researchers also designed an experiment with injections of sodium fluorescein for acupuncture points and indocyanine green, a contrast agent used primarily for lymphography. The results showed that the two trajectories did not overlap, so the possibility of a lymphatic vessel could be ruled out.
The authors concluded that veins or lymphatic vessels could not have been responsible for these trajectories.
Injection of dyes at non-acupuncture points produced only local isotropic diffusion without migration into a meridian pathway.
Tongju Li, Bruce Qing Tang, Wei-Bo Zhang, Minyi Zhao, Qingchuan Hu, Andrew Ahn, "In Vivo Visualization of the Pericardium Meridian with Fluorescent Dyes", Evidence-Based Complementary and Alternative Medicine, vol. 2021, Article ID 5581227, 10 pages, 2021. https://doi.org/10.1155/2021/5581227