Relationship between shape of peripheral initial lymphatics and efficiency of mechanical stimulation–induced lymph formation

AbstractObjectiveThe present study aimed to combine the physiological significance of irregularly shaped initial lymphatics and mechanisms of mechanical stimulation–induced lymph formation.MethodsTo confirm stretch‐induced expansion of initial lymphatics, a finite element model that simulated morphological changes on a computer and fluorescent image and immunohistochemical analyses in mouse skin were adopted. Next, to quantitatively analyze the stretch‐induced expansion, a simulation study was performed using a viscoelastic model of the tissue including initial lymphatics.ResultsOn the finite element model, when the tissue was stretched, irregularly shaped lymphatics were confirmed to increase luminal volume compared with round‐shaped lymphatics. Stretch‐induced expansion of the real initial lymphatics was demonstrated by fluorescent images and histological studies. Thereafter, with the application of a viscoelastic model of the tissue, the relationship between the lymph formation rate (Q) and massage frequency (f) could be obtained using the following equation: , where A and τ are constants. Excellent agreement was found between the previous data and the results of the present equation.ConclusionsWe conclude that irregularly shaped initial lymphatics may lead to efficient lymph formation induced by mechanical stimulation of the tissue.