Background:Observing interstitial fluid(ISF)is very difficult because interstitial structure collapses and ISF disappears after tissue fixation.Additionally,ISF is colorless,and interstitial flow is weak in vivo.In order to view the interstitial flow,special dye and animal model was chosen to explore the movement characteristic of interstitial flow and related structure.Methods:The Gephyrocharax Melanocheir(GM)fish,a special animal with translucent body,were placed into 0.03 g/L tricain solution for anesthesia.20-25μL Alcian blue(AB)solution which can stain acid mucopolysaccharide immobilized by the collagen net in connective tissue was injected into each fish at a single point with a rate of 2 μL/min via a micro-injection pump.The process of infusion and the movement of the AB in fish were record by a digital camera.The(fresh)frozen sections of AB tracks tissue were performed to observe the morphological feature.Results:Several blue tracks were observed which were formed by longitudinal directional movements of AB solution.For back lateral track,the velocity and length of the movements were significantly fast and longer on the direction toward head than that toward tail(P<0.01).For lateral middle track,the result was opposite,namely toward tail(P<0.01).This phenomenon indicated an inherent ISF flow according to Darcy's law.Morphological study showed these tracks were just in septa composed by connective tissue.The stained blue septa formed various shapes as interstitial space for ISF flow and connected with one another like a net.The finding can help us to understand the essence of meridian in traditional Chinese medicine(TCM).Conclusions:The dynamic asymmetry of the AB tracks revealed interstitial flow in the GM fish body.It implied an inherent interstitial flow along particular pathway formed by septa which may be a key to understand the nature and value of meridians and collaterals in health care.
Background:Continuous and porous low hydraulic resistance channels(LHRCs)are important structures of meridians in traditional Chinese medicine(TCM).In this study,based on the previous research on LHRCs along meridian paths(LHRCMs)in mini-pig,we aimed to detect the low hydraulic resistance point(LHRP)and display the LHRCMs in rats.Methods:A technique for measuring interstitial hydraulic resistance(Rh)in rats was established to detect and measure the Rh along the conception vessel(CV)in TCM,and Alcian Blue(AB)solution was injected into the LHRP along the CV.The interstitial fluid pressure(IFP)of the LHRP was measured before and after AB injection.Then,the distribution characteristics of the AB solution were investigated to explore the relationship between AB tracks and meridian paths in TCM.Results:The positions of the LHRPs coincided with the low impedance points(LIPs)of the rat skin along the CV.The Rh value along the CV(10.37,1.26,×10^(6)dyne s cm^(-5))was significantly lower than that in the non-meridian area(19.13±1.37,×10^(6)dyne s cm^(-5),P<0.01).After AB injection,the IFP of the LHRP was 2.52 mmHg,which was higher than that before AB injection.The AB tracks(ABT)along the CV,spleen meridian,and kidney meridian appeared in one or two directions,with single or multiple paths and uneven thickness and length.The appearance rate was 73.33%.Conclusions:LHRCMs existed not only in minipigs but also in rats.The LHRCMs could be observed after AB injection into the LHRP in the subcutaneous connective tissues of rats.
