Abstract
Interstitially administered colloidal particles are known to accumulate in the regional lymph nodes. Recently, radiolabeled colloids, such as 99mTc-Sulfer colloid and 99mTc-Rhenium colloid, are used for lymphoscintigraphy and sentinel node navigation surgery. Accumulation of interstitially injected colloidal particles in the lymph nodes involves the following three steps; uptake of the colloids at the initial lymphatics, transport of the colloids through the collecting lymphatics, and retention of the colloids within the lymph nodes. In this study, we focused on barrier function of the regional lymph nodes in order to investigate characteristics of colloidal retention within the lymph nodes. Centripetal and retrograde cannulations were performed into the popliteal afferent and efferent lymph vessels in Japan white rabbits, respectively. The lymph nodes were selectively perfused (injection rate: 0, 0.74, 1.47, 3.68, 7.35 and 14.7 ml/h) with artificial lymph fluid (HBSS with 2.6% BSA) in the absence or presence of fluorescently labeled microsphere. More than 80% of the volume of the fluid injected into the afferent lymphatic was collected from the efferent one. No microsphere of 2.0 μm in diameter injected into the afferent lymphatic was appeared in the efferent one. On the other hand, microspheres of 0.2 μm in diameter injected could be observed in the efferent lymph vessel. These results suggest that this preparation is useful to evaluate physiological and pathophysiological function of the lymph nodes in-vivo. [Jpn J Physiol 54 Suppl:S105 (2004)]
