Development of a fluorescence stereomicroscope and observation of Bong-Han corpuscles inside blood vessels.

A fluorescence stereomicroscope system was developed in order to observe in situ the distribution of nuclei in intravascular Bong-Han ducts and corpuscle tissues by injecting acridine orange, which stained specifically nuclei. Intravascular Bong-Han corpuscles, connected with Bong-Han ducts could be detected in the aortas of rats, mice, and rabbits.

In vivo visualization of bonghan ducts inside blood vessels of mice by using an Alcian blue staining method.

An in vivo method using Alcian blue (AB) was developed for visualizing floating threadlike tissues inside blood vessels of mice. These novel structures called intravascular Bonghan ducts (IBHDs) are considered as extension of acupuncture meridians. For in vivo imaging of IBHDs, AB solution (pH 7.4) that stains mucopolysaccharides like hyaluronic acid was used. After injecting AB solution into the femoral vein of a mouse, the threadlike structures, stained deep blue, inside the inferior vena cava. The histological results, such as hematoxylin, eosin, and AB staining, show the compositions of the cells and the extracellular matrix in the IBHD. Further studies are needed to investigate their physiological functions, especially in relation with those of other circulatory systems.