The first documentation that clearly describes the meridians was the Huangdi Neijing (given the title The Yellow Emperor’s Classic of Medicine in one of the latest translations), dating from about 100 BCE. This description has been traditionally accepted and used as a basis for acupuncture theory and practice for over 2000 years. Since the early 1950s, researchers have tried to prove the physical existence of these meridians. Much of acupuncture’s scientific skepticism is partly due to the unknown anatomical foundation for the existence of meridians. The Standard International Acupuncture Nomenclature proposed by the World Health Organization, and based on TCM texts, describe 12 organ meridians and eight extrameridians – 20 meridians in all. The anatomic structure of meridians has remained undiscovered till the 1960s.
Bong-Han Kim, a professor at the Pyongyang Medical School in Seoul, North Korea, embarked on scientific research to discover the substratum of the meridian system (Kyungrak in Korean). While head of the Department of Physiology, Kim announced his discovery of this anatomical substratum, calling it the “Substance of Kyungrak,” on August 18, 1961, which he then published in 1962. Kim then proposed a system he called the Bonghan Ducts as the physical basis for the Traditional Chinese meridian system. Kim subsequently published 6 articles and a book on his research from 1962 to 1965. 1-7
Kim described nodes and ducts that corresponded to traditional acupuncture points and meridians. He called these nodes and ducts Bonghan corpuscles and Bonghan ducts after his own name. In the 1962 publication, he wrote that the substrate of the meridian system “consists of bundles of tubular structures and it is clearly distinguishable from nervous, blood vessels and lymph systems in histological and experimental-biological characters” and ”the diameter of the tubular structures range between 20 and 50 µm.”
Kim used several experimental methods in determining this such as anatomical methods, histological methods, radioautography, histochemical methods, blue staining methods, and radioactive dosimetry. In his analyses of the Bong-Han system Kim found that the transparent fluid inside the ducts contains more nucleic acids, especially DNA, than any other known tissue. The Bong-Han ducts also contain sanals, meaning “live egg” in Korean, which seem to have a function equivalent to that of stem cells. Kim described these sanals, renamed primo microcell or P-microcell, as having hematopoietic functions as well as the ability to regenerate injured tissues and heal wounds.
Bong-Han Kim’s work was largely ignored until in 2002 at the Seoul National University a team of researchers led by Professor Kwang-Sup Soh investigated further and conclusively confirmed that this system represented the physical construct of the acupuncture system.8, 9, 10, 11 They renamed it the Primo Vascular System (PVS) and have shown it exists in the same locations as the traditional meridian system acting as a third circulatory system after the cardiovascular and lymphatic systems. Numerous others since have further described these Primo vessels as having bioelectrical activity, excitatory conductivity, and mechanical motility.12, 13, 14, 15, 16 Over several investigations have discovered these primo-vessels (Bonghan ducts) and primo-nodes (Bonghan corpuscles) in various animal tissues and organs - mouse, rat, and rabbits.
According to this research the PVS integrates the features of the cardiovascular, nervous, immune, and hormonal systems. It provides a physical substrate for the acupuncture points and meridians. Announcements of the morphological architectonics and the function of the PVS fundamentally changed the basic understanding of biology and medicine because the PVS is also involved in the development and the functions of living organisms.
Korean researchers discovered a liquid, called “the primo fluid”, that circulates in the PVS. Its flow is slower than blood flow and lymphatic flow. The primo fluid flows in one direction, attending blood flow. The liquid flow depends on the heartbeat and on the pressures of the blood and the lymph. The PVS fluid has DNA outside the cell nucleus. The biochemical components of primo fluids are DNA, RNA, nitrogen, fats, reducing sugar, hyaluronic acid, 19 free amino acids, and 16 free mononucleotides. The routes of flow are interconnected, but relatively independent. Primo fluid circulates only in a specified region, but it can also be transmitted through interconnections with other pathways.
The subvessels of the PVs are composed of endothelial cells with rod-shaped nuclei, smooth muscle cells, and adventitia. Fiber structures and amorphous substances exist among the subvessels. A membrane surrounds the whole primo vessel. The constituents of the PN are the subvessels and various cells. The subvessels are densely distributed, enlarged, and connected to each other. Kim developed his idea for the PVS by adding interior and exterior PVs.
As previously mentioned, the PVs have bioelectrical activity, excitatory conductivity, and mechanical motility. The electrical activity changes in relation to stimuli to the PVs. The PVs have mechanisms to circulate the primo fluid actively. All nuclei of the tissue cells are connected to fine terminal subvessels, and these subvessels are connected to the primo vessels in a body's organs. The PNs in an organ are connected to the organ's tissue cells within a specified range. All PNs for the organs are connected to all meridians. The meridian structures start and end at the PNs for the organs.
It has taken over 2000 years to validate the meridian system originally described in the Huangdi Neijing. Kim and Soh’s research toward the meridian system has now fostered many others to further explore the PVS. The discovery of the PVS in intravascular and extravascular spaces, in the central and peripheral nervous systems, on the surface of and within viscera, in cutaneous layers, and in most body systems, may signify a novel and complete morpho-dynamic system, with the potential to reshape paradigms in medicine and especially energy medicine.
This video explains the PVS using a staining dye injected into the body. In their video example, they chose to look at a section of PVS inside of a Lymph vessel because the normally transparent tissue will clearly elucidate with the dye. The width of these tubes is 20-30 micrometers; contrast that with the thickness of human hair 60-120 micrometers.