Spectrophotometric determination of dye accumulation in the lymph nodes of mice: a comparative study between local massage and exposure to multidirectional vibrations in the horizontal position.

Background : Whole body vibrations (WBV) are frequently applied by sportsmen, in well-being centres, and for medical conditions. The physiological effects of these vibrations have been studied extensively.Objective : Analysing the short term effects of multidirectional vibrations delivered in a horizontal position (andullation) and local massage on the accumulation of dye in the lymph nodes of mice.Methods : Whole body vibrations at 30 Hz in a horizontal position (andullation) during 5 minutes as well as local massage for 5 minutes are applied ensuing injections of 20 µl Evans blue dye (EBD) in the foot-pads of 2 randomized groups of mice (total N = 15 animals). Both groups are compared to a non-treated, randomized, but similarly injected control group (N = 10 mice). Following animal euthanasia, the EBD-stained popliteal and sacral lymph nodes are carefully resected and their contained blue dye extracted. The quantity of EBD (µg) is determined using a spectrophotometric technique with a wavelength of 620 nm.Results : As a result of total body vibrations in the horizontal position the quantities of EBD in the popliteal lymph nodes were statistically higher compared to the control group: respectively 0.56 ± 0.26 and 0.14 ± 0.17 (mean and sd, p˂0.05). The quantities of EBD also differed statistically from the recorded quantities following massage: respectively 0.56 ± 0.26 and 022 ± 0.16, mean and sd, p˂0.05). The quantifications of EBD in sacral lymph nodes revealed strictly identical values.Conclusion : The presented experiment in mice indicates that high quantities of EBD are accumulated in the lymph nodes following a short whole body exposure to multidirectional vibrations (30 Hz) in the horizontal position. The quantity of accumulated dye is higher than when local massage is performed at the dye-injection site or without intervention.The specific tracer accumulation in the lymph node is an important lymph function parameter and depends on the quality of lymph reabsorption and lymph flow.