Catecholamine-producing novel endocrine organ: Bonghan system

Background: In the early 1960s, Korean anatomist Bong Han Kim proposed the existence of a circulatory system that could be the anatomical basis of classical acupuncture points and Meridians. Henceforth the corpuscle-like structures corresponding to acupuncture points were referred to as Bonghan corpuscles (BHC). These initial observations used only relatively simple bioanalytical methods and light microscopy. Objectives: To detect catecholamine-producing cells and to measure the adrenaline and noradrenaline concentrations secreted by them in the BHC. Design and Setting: From April-June 2006, experiments were conducted on 6 female New Zealand white rabbits in Korea. The BHC were sampled at the surface of rabbit internal organs, the presence of catecholamine cells was evaluated by immunohistochemistry, and adrenaline and noradrenaline levels were measured using the biochemical methods. Main Outcome Measure: Mean concentrations of adrenaline and noradrenaline in the tissue samples. Results: Immunohistochemical analysis revealed that only cells of mixed type (adrenaline + noradrenaline) and with relatively high concentrations of adrenaline compared with noradrenaline were found in the BHC. In the BHC extracts, the adrenaline level was significantly higher (mean [SEM], 20.6 [8.8] ng/g) than the noradrenaline level (5.8 [2.6] ng/g). However, in other tissues (adrenal gland, heart, and urine), the adrenaline concentrations were lower than the noradrenaline concentrations. Conclusions: Together with the adrenal medulla and sympathetic ganglia, the BH system is thought to be a physical substrate of the acupuncture Meridian system and may represent a novel source of catecholamine synthesis, storage, and, possibly, signaling.