抄録
Lymph nodes are known to exchange hydrophilic substances between the lymph and the blood compartments. Usually small molecular substances are absorbed to blood vessels and consequently lymph protein concentration increases in the lymph nodes. In this study, we focused on exchange of water through the lymph nodes in vivo. Male Japan White rabbits were anesthetized with pentobarbital sodium (20 mg/kg iv.). Retrograde cannulation was performed in one of the popliteal efferent lymph vessels at the groin. All other efferent lymphatics were ligated completely. Then, centripetal cannulation was performed in one of the popliteal afferent or efferent lymph vessels near to the lymph node. Physiological saline solution was infused through the upstream cannula. Lymph outflow rate was determined at the constant outflow pressure of -5 cmH2O. Lymph outflow rate increased monotonically with protein concentration of infused solution (0, 2.6 and 10% bovine serum albumin) and with venous pressure of the hind leg (control, 20, 30 and 40 mmHg). No apparent change was observed after decrease of arterial pressure of the hind leg. From these results, colloid osmotic pressure and hydrostatic pressure may have important role in penetration of hydrophilic substances in the lymph nodes. [J Physiol Sci. 2007;57 Suppl:S205]
