Purpose: To examine the extracellular (dispersed particles) and intracellular (phagocytosed particles) colloidal particle transport from subcutaneous tissue into the lymphatic system.
Materials and methods: Perfluorocarbon emulsions LA11063 (mean particle diameter, 0.34 micron) and ZY12149 (mean particle diameter, 0.06 micron) were individually injected into the dorsal skin of the hind foot of rabbits. Lymph flow rates and particle concentrations were determined in prenodal lymph fluid after injection, with and without massage of the skin over the injection site.
Results: In the first 24 hours after injection, extracellular colloid flux was substantially larger than intracellular flux. Lymph flow rates and colloid concentrations increased substantially with massage. Extracellular LA11063 flux was smaller than ZY12149 flux, whereas intracellular LA11063 flux exceeded ZY12149 flux.
Conclusion: Transport of colloids into lymphatic vessels is dependent on particle size. Both extracellular and intracellular pathways are utilized. External tissue movement contributes substantially to the rate of particle uptake via both pathways.