Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles

Abstract

The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson’s trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density.

Distribution of Mast Cells and Locations, Depths, and Sizes of the Putative Acupoints CV 8 and KI 16

“…Therefore, the finding that the population of MCs is denser at APs and meridians than at nearby nonacupoints is not surprising [4, 5]; stimulation of the APs by using electroacupuncture or moxibustion has been found to induce degranulation of MCs [6–8]. This cytological characteristic of APs is in accordance with the recent finding that a particular tissue, called the primo node, in the primo vascular system (PVS) has a high population density of MCs [9]. The PVS was first proposed as the anatomical structure corresponding to the APs and meridians by BH Kim in the early 1960s, and it has long been thought, but not proven, to be a possible scientific foundation for Korean medicine [10].…”

“…Both the long fat band in a rat and the fat pad in a mouse are populated with MCs. The fat band of a rat has a PVS in it, and high densities of MCs in the PVS have recently been found in several works on the primo nodes in the abdominal cavity [9, 21–23]. …”

“…Therefore, the question of whether the densities of MCs in the skin could be used to get information on the locations, depths, and sizes of APs was not answered. Independently, the evidence for higher densities of MCs at APs was reinforced by a series of works on the abundance of MCs in the PVS in the abdominal cavity [21–23] and the abdominal wall [9]. This PVS prompted us to develop the current scheme of estimating the anatomical parameters for the APs in skin by making use of the distribution of MCs.…”

The Cellular Architecture of the Primo Vascular System

“…Despite its very long history of use, acupuncture remains not well understood, despite its increasing worldwide acceptance as an effective treatment option [2]. A relationship between the PVS and acupuncture meridians has been described [10,41,42]. Also, some cupping points were described as part of the meridian acupoints system [43].…”

Traditional Acupuncture Meets Modern Nanotechnology: Opportunities and Perspectives

“…In order to elucidate the functional and the medical aspects of the PVS, fluorescent nanoparticles could be used as contrast agents. Several kinds of fluorescence nanoparticles have been developed by using silica loading fluorescence dyes, including the rhodamine B isothiocyanate [32–34], and a mixed dye of commercial Pelikan ink and rhodamine B [35] to observe the PVS in the abdominal wall, epineurium along the sciatic nerve, the subcutaneous layer of skin, and even the fourth ventricle and spinal cord. These nanoparticles were detectable with MRI [36].…”