EXTRACELLULAR AND INTRACELLULAR-TRANSPORT OF PERFLUBRON EMULSION (IMAGENT(R) LN) FROM SUBCUTANEOUS TISSUE TO REGIONAL LYMPHATICS

The purpose of this study was to examine the uptake mechanism of collo idal particles from subcutaneous tissue into initial lymphatics. The s tudy was performed on anesthetized rabbits using Imagent(R)LN, a 60%w/ v perflubron (perfluorooctyl bromide [PFOB]; Alliance Pharmaceutical C orp., San Diego, CA) emulsion. Extracellular (dispersed particles) and intracellular (phagocytosed particles by macrophages) perflubron tran sport was observed in lymph fluid after 0.1 ml injection of fluorescen tly labeled perflubron emulsion into the dorsal skin of the foot. Samp les were collected from cannulated lower leg prenodal lymphatics. Perf lubron emulsion particles were visualized and quantified by using a fl uorescent technique. Extracellular and intracellular perflubron could be determined in the lymph samples. These findings indicate that both intracellular and extracellular transport mechanisms play a role in th e uptake of colloidal particles from interstitial tissue to lymphatics .